I'm thinking about making a dedicated gaming PC which is to be shared in our household. ChimeraOS/HoloISO seems the ideal solution to that... Except that games thay it means that all save files of games that don't use Steam Cloud OR write save files on Valve's recommended directory are shared between users.
Is there any tool that can recognize the current active Steam User and swap save files on the background? The other solution is to forego using HoloISO/ChimeraOS/SteamOS and install a traditional distro and make different users have different system accounts, but that sounds a nightmare to deal with due to Steam Family Sharing requiring that all steam users are logged into each system users, so the library is shared across all of them. Not to mention config files are going to be separated as well...
I understood all that from your post. I'm just saying that if the distros end up being as inflexible as you've described, you may need to look for a way to get flexibility at a different level of the "stack."
You can add and launch arbitrary non-Steam games from Steam, right? Can you use Steam to launch a script that moves around files in the background and relaunches Steam? And have a named launcher to "switch" to each user?