How to Play with Multiple Versions:

Copy your Dom2.exe.

Rename Second Copy to "Dom211.exe"

Check all your Shortcuts to games and modify their command line from Dom2.exe to Dom211.exe for all games not upgrading.

Patch to 2.12.

Check all your shortcuts to games for 2.12 and make sure the command line is Dom2.exe.

Remember which Version you are playing for what games.

Games are only compatiable if they are the same Version. I hope that Mose will tell you if/when he updates and for what games.