Thanks for your input. I actually saw this particular scenario from a guy who played. The exact same room with the chest as you are referring to. Luckily he didn't clip through the wall. I did some testing and it happened to me. That's why I made the invisble platform. How to solve the issue, I don't excactly know for the time being.
I didn't know about the barrel. Thanks for pointing that out.
About the endings - I have a document which describes each end scenario in detail. At the moment, there are two endings (5 & 7) which can't be achived yet, because I'm missing implementing the last AI. I'm truly sorry if you have spent time in vain looking for those.
I can send you the document to your mail/discord, or give some hints instead if you prefer.