Since I don't believe this will ever get to a point, where it's worth setting up a Discord, I am going to dump some findings in here for future runners.
Reject death glitch
This one is probably always going to be useful. Essentially when you die, when the game asks you which save to load, you click X on the top to continue playing. You are going to be in a bugged stated, which depending on - what I think is - the way you die will result in the state in which you can go through geometry. To return to normal state, simply save and load after rejecting death - this however can result sometimes in the game softlocking.
The glitch was likely found already in 2019, but a video was never posted until TheKotti showed it to me during ESA Summer 2024.
Buffered reject death glitch
This one is less useful, but might help to prevent some softlocks. Since opening menu takes a tick, you can try and buffer a menu open and open a menu after you die. This way, you can save in a dead state, although the game will still display respawn menu no matter what you do.
