If I am reading you correctly, what you are describing as choosing to “turn off” optional objectives is more accurately described as “auto-win”
As absurd as I find this, maybe you could research creating a mod to do this - IOI certainly aren’t going to entertain such a change.
I don’t know about “auto-win,” I just want to play the mission the way I want with nothing in place to keep me from getting the maximum reward without following them. Just like normal campaign play, but with payment.
Mods aren’t the real game. If IOI isn’t going in give us a Freelancer without the objectives -at least for this game - then I guess I just won’t have it.
Yeah that’s not a bad idea to be honest 
Good news: I did it.
Bad news: game crashed (again) while I was at the supplier before exiting so officially, I did not accomplish it.
Conditions:
territory: showdown on Whittleton Creek
complications: No Bodies Found, Melee Weapon Kill, Poison Target - Sedative
prestige objective: initially “Collateral Kill - Accident”, but reverted to “Silent Assassin” in 2nd / final attempt.
I was very fortunate that the syndicate leader was the sole suspect to “patrol” into Cassidy’s home (no assassins, no lookouts nor other suspects) so I was able to use the fumigation machine to subdue the entire home and its occupants, includig Cassidy, his bodyguard, and my target. Then it became a festival of subduing and hiding those bodies to ensure no one saw the unconscious target and a guard between Cassidy’s house and dumping into the creek. Finally complete, I visited the supplier and while clicking on sedative poison vial (choosing the lower right-hand item caused previous crashes, but does not crash the game every time), game crashed.
Gave up on “Collateral Kill - Accident” (too stressful to lure, subdue, and hide the ancillary people) and changed to “Silent Assassin”. Got the courier and safe’s Merces then visited the supplier. After gassing the target (this time, he very nearly opened the front door due to tight timing), went inside the house and threw a cleaver at him then left without re-visiting the supplier.
I confess to visiting the supplier after completing everything because I would like to carry out large items without forgetting or having them found if I drop them after buying earlier.
The other common denominator for the crashes is when the mission is >1.5 hours, but then every one of my Freelancer missions is long, most averaging ~2 hours.
Thanks again to melusca, olipro, and lindolfo who provided the advice about push / dump rewarding for the collateral kills + melee kill + drowning.
Best regards.
Edit to add a link to a time-stamped bigmooney06 Freelancer videowhere he shows a crash very similar to my experience, including that micro stutter visible just before game freezes then crashes, except his incident was in March 2023; there have been several updates to the game since his video.
I don’t know how this video is proving me wrong? It’s proving me right. By not running you missed the extra merces from the previous campaigns final mission.
Here’s my video actually getting an extra 6.5k from the final mission. My way is better 
Now I understand you. Yes, if you rush it’s possible to also secure the regular objective payout. You don’t need to rush in order to get the 30K from the chest nor the 30K campaign completion bonus.
In your video, you end up only marginally better off. Had you opened the chest beforehand (thereby likely sacrificing the 6,500) you would have ended up with 60K. However, since the Silverballer is worth 24,700, with the objective payout preserved, you’re doing slightly better than the no-rush strategy.
In any case though, you are rolling the dice on the game giving you a legendary weapon that has a value complementing your objective payout.
Depending on how well you did completing objectives, it may or may not be worth it - additionally, it’s predicated on you not messing up. You can take the 60K with zero risk, or try to rush it and hopefully bag a good weapon along with your objective payout.
I could still do the 60k strategy with the run method, I was a little slow in my video tbh. Regardless I think if you are playing hardcore you’re better off with the Legendary weapon. Just because it’s nice to be able to fulfill prestige objectives right out of the gate without visiting an arms dealer first and hoping he’s got a legendary for sale.
I’ll concede on regular mode 60k is probably better because you don’t have to fulfill prestige objs so you can gamble with the arms dealer more.
One thing I truly love about Freelancer, and am glad they put it in, is also something that you can do in most Assassin’s Creed games, and Grand Theft Auto games, and that is stealing the money from your targets. In the Assassin’s Creed games, there are stashes and chests of money and gold all over the place that are being used by your enemies or other dirtbags, and you can take it from them to finance yourself and weaken them. In Grand Theft Auto, you can take any money a person you kill has on them. And of course, in Freelancer, you can take the money from the couriers and from safes as you see fit. I always do this unless I’ll fail some objective in the course of doing so, which is extremely rare.
I love the fact that, not only is this getting 47 richer, not only do the syndicates not deserve the money and weren’t going to use it for anything good anyway, not only is a callous calculation of, well, I’ve already killed them, might as well take their money too, but it also serves the purpose of weakening the syndicate as you deprive them of not only members but crucial funds for their operations. If you play Freelancer as a continuation of the ongoing Hitman story, as I do, then the satisfaction of making yourself that much richer and your enemies that much poorer actually serves a narrative purpose.
I don’t know why, but I just felt like talking about that, as my most recent success over a particularly difficult campaign has me almost giddy over robbing criminal dickheads blind while also killing them off.
You play Freelancer exactly like me and how it’s supposed to be 
Natural poison
What maps offer the best to create Natural poison lethal ?
Whittleton creek , the Frog behind Batty’s house.
Santa Fortuna
Berlin ? I know there are some plants but not sure if you can create a poison in game. Is there equipment near the tower shed ?
Mendoza
Also outside 47 home, you can make poison but haven’t tried to bring it in the game. Has anyone?
Any other maps ?
Then again I have to hope
Foodie
Dehydrated
I don’t think there’s a natural syringe option
Berlin has an emetic mushroom, never seen a lethal in freelancer.
Haven Island has lethal frogs.
Ambrose Island has lethal frogs.
These are the ones I remember.
The list of maps with natural poison to my knowledge:
Santa Fortuna – lethal frogs as well as a lethal flower (in the overgrown area with a dead bodyguard)
Whittleton Creek – lethal frogs
Haven Island – a lethal frog
Dartmoor – a distillation kit that allows you to convert any emetic poison into lethal one (requires a wrench to repair)
Mendoza – a distillation kit that allows you to convert any emetic poison into lethal one
Ambrose Island – lethal frogs in ruins as well as an emetic flower that can be converted into lethal flower with the help of the research student.
The poison that you can craft at the safehouse does not count towards the challenge in my experience; please correct me if I’m wrong
By the way, fumigating rooms with a poison also does not count towards the challenge as far as I could tell.
Santa Fortuna has two more lethal flowers in the area where the shaman is.
Fumigating might work if what you put in is natural vial but I don’t think it’s possible to try.
Unless you can use the frog in the fumigating in whittleton creek. But a vial might be a requirement if so then it won’t work.
I’m surprised Colorado doesn’t have any options as big as it is.
Anyway I’ll try
The distillation kit is not present in freelancer.
Only consumed poison counted for natural selection, this could have changed since I completed it last year but I don’t think so.
I just found out while on Dartmoor the distillery kit is not present in Freelancer which is stupid.
So for now I’m using
Mendoza
Whittleton Creek
Santa Fortuna
I haven’t tried to yet but thought about seeing if the frog behind Battys house would work on the fumigation, or must it be in a vial
But on dehydrated and foodie you can poison with the frog directly.
Update :
It will give me the option to use the frog on the fumigation machine, but won’t count towards natural
There are also poisonous frogs on Haven and Ambrose island, and poison that can be crafted on Ambrose as well. I don’t know if Dartmoor has the poison frogs that the Garden Show version has, but if so, there you go as well.
I’m fighting with myself. A part of me wants to finish Freelancer as soon as possible completing 100 campaigns and killing 500 leaders (I miss 27 campaigns and about 120 leaders). But another part is bored and wants to play other games. Ignoring objectives I’m completing campaigns a lot faster. But I still miss so much ones
I have used the frog on a leader at least two times in Cassidy’s house and it didn’t seem to work towards the challenge. Would have been cool if it did though.
If you’re not above cheating/exploiting how the game works - when you get to the end of a campaign and you exit after killing the leader: Alt+F4 while the exit cutscene is playing.
When you load back in, you will be back in the safehouse like you haven’t played the final Showdown - but your challenges will have increased their totals by one.
Rinse and repeat.