I actually looked in to releasing it for Linux already. Problem was the Nvidia DLSS plugin does not support compiling for Linux. I could remove it and package for Linux separately but considering the high rate of iteration currently and the low amount of Linux users that won't be a reality until the game is released.
However I have seen some users getting it to run using some variation of Wine/Proton. Unreal games in general seem to work well on Linux as far as I understand.
Until release that is sadly the best I can do without stealing too much time from development. As a Linux user myself (I run Arch, btw..) I very much would like to add support for Linux.
Mac is a different issue as I would need a mac to test on and I don't think I will buy that just for testing it out. Remember I'm doing this in my spare time for fun and everything comes out of my personal pockets. I'm not a publisher, game company or even a company. My marketing budget is 0 and every penny goes into the game itself.
I haven't looked in to what is needed to package for Mac, maybe it is possible to do it blindly from windows. That could work if I had people volunteering as testers.
Regarding the zip issues some seem to experience while most does not. I can provide a 7z mirror if you believe that would help. I have heard the same thing regarding big zip files.
Also thank you for taking the time to write up the feedback. Always appreciate input!