To do multi-user correctly it will take them rearchitecting a few things. Here’s what I’d image is currently required:

1. Game artifacts would need to move into a common area to prevent duplication (or utilize a COW filesystem)
2. Game compat data will need to move under the user home directory and not immediately live with the other artifacts like it does now
3. A new login screen will need to be created that actually switches between system users (will need to use some password separate from an account password for offline use)
4. Some extra state tracking may be useful. Switching back and forth between desktop and game mode will prompt the account switch menu but some data can be stored to make it remember who the current active user is…

Most of the tools to do this are already present but it’ll take some time for someone to coordinate it and the fact that the product has made it this far without such a feature speaks to it’s demand. Hopefully someone takes a look at it though because it really shouldn’t be that bad.