Couple new things I figured out recently which make this speedrun way more interesting and skill based.

Rappel skip in Prologue:

You need to take over a health bar of damage so you can use your medical items even after the automatic regen. Right in front of the spot you have to snipe enemies from is a cliff that you can safely fall down on. To skip the scripted death barrier you just use a med item right before hitting the trigger. After you've fallen down you need to move forwards immediately or you will die.

At the moment this skip can only be done after you've spotted all 6 enemies and done the zoom/zeroing tutorials so you can shoot the enemies, then you need to shoot all 6 enemies as well but it doesn't matter where you do this from. Otherwise the game is softlocked since the next group of enemies inside the factory don't spawn and the game will fail you when you go too far forwards. There might be a way to do this skip earlier but I didn't look too much into it. The current skip saves over 40 seconds when done quickly.

"NG+" Fast Travel Point Bug:

Sometimes you might notice a Fast Travel Point (FTP) being unlocked on your map even though you haven't been near it yet. This can be replicated 100% of the time and is currently used to save 35-40 seconds in Grave Diggers. For the current route you should bug the FTP near K'vanakhshiri Mine since that is one of the most important FTPs so it shouldn't be skipped and it should be the fastest during the entire run in my opinion. As far as I know this bug can only be done on one FTP in a run and only works in the first map.

To do this bug you need to do a pretty simple although somewhat time consuming step before every run, unless you reset in Prologue in which case the bug will keep working. I would recommend making a copy of a safe file before Grave Diggers mission so you have less FTPs unlocked (save files are located in <Steam-folder>\userdata<user-id>\368070\remote\savegames\ , copy the entire savegames folder). For the bug itself, you need to start a mission and drive to the FTP you want to bug. After you have unlocked the FTP you just reload last checkpoint, quit to main menu and then you can start a new run and the FTP should be unlocked for you.

Once again there might be an easier way to do this bug or even bug multiple FTPs so definitely recommend doing science on this. Find a way to bug out all FTPs would save minutes across the entire run.

Tornado jump movement:

This is going to be the main movement tech in the game but it's really new and probably not understood well enough to be done optimally. For some reason holding W + A or D and spinning in the same direction gives you a weird speed boost. You can do full 360 spins to gain a speed boost forwards. You will lose the speed boost pretty quickly on the ground however if you jump after the spin you will keep all the momentum in the air and can then chain together more spins to gain even more speed. You have to be careful though because if you go too fast or land too low, you will just die from fall damage. 3-4 chained spins is the maximum I was able to do on even ground without dying.

This tech can technically save time anywhere where you are just running, however you need some room to do it properly so it is hard in tight spaces or places with a lot of objects like trees etc, or at least it was hard for me. The sky is pretty much the limit with this tech and it will make movement actually matter. The tech has to studied more as well so we can understand what's the best way to do it. So far this is also useful for a small skip in Awas' Family where it allows you to exfiltrate the area way faster than before by jumping kinda out of bounds.

Clip example of the movement in action:

https://www.twitch.tv/whose_that/clip/ArtisticColdbloodedReubenBIRB-EkiLjkfE2-ZK2kB8