7zip mirror (0.4), hopefully that will help!
https://mega.nz/file/t8UhGKCK#a0cVK7QiLABgDHF_CmtAHOwSGe7xSnsfrzQr_czPHvI
As for the development everything is done in Unreal Engine blueprints which is platform agnostic. The only things that are specific are the plugins. It's up to the engine to make sure it runs on different platforms and I doubt I can make a better job than ID in that regard :)
I'm also not looking at getting into development or the gaming industry, it is purely a side project for me and will remain such (unless I'm wildly successful and can retire early but that is not something I'm expecting, I'm just hoping to get my investment back).
But thank you for the input and well thought out replies. Highly appreciated!