Marking this thread as solved, at least for the Hollow Knight part, vv221 is my new bestie and was able to help me get that working and shed some light on what the problem was for that:)
It didnt solve the Subnautica issue tho from what I just tried fiddling with again since this new light, SO, if anyone at any point would have some hint, a clue, and solution that makes it work for me, I will gift another copy of HK away, or another game if u prefer within the same price limit of gifting (~30 euro), so hit me up here or in pm if u think u know what it is whether complicated or its just me just being a noob and its the simplest of thing to tweak, im open to suggestions:)
I also would love to get Stranded Sails working, BUT I need to check the GOG version first, to see if its only my steam version that wont work(which many reported this same issue with since day one pretty much, so it might simply not work im not sure:)
Scroll bk and through all the rambling to update what was tried and not if u care, if not good day and ty to all the ones that peeked in with suggestions here so far, I appreciate it!
Consider it closed (but still open haha), and maybe in another 3 yrs ill make another post to get Sub running once again, or maybe GOG will get it to the store b4 that, lets hope! :)