i had NEM before the spooky update when it got unplayable,  so i followed a tutorial to download an older version of project nexus and get NEM on that version, and now i played legacy of the s3lf eater on non NEM version, and im scared that my save files will get deleted, so does it work on the latest version?

Well before you do anything backup your save files

Hi. I'm pretty sure the vid you followed was based off my guide. If it's this video (Look below) then I made that guide. Don't worry about saving. The cloud save is your save related to steam, aka the real game. Your local save will be the modded one since it's not connected to the cloud, but rather your computer. Do not worry about saving at all, and if you have anymore questions.