I also came here to post a similar grievance, but the problem is actually in how the mod unlocks uncommon quality for the player. The game must validate quality unlock levels when loading a savegame, because the uncommon quality is no longer available after loading a savegame with this mod. This is because the function where this mod unlocks the quality (on_init) is only ran when first creating the game world or loading a game that didn't previously have this mod installed.
Could you do something to make the uncommon unlock persist please?
^ This command is the same as what the mod uses. You can enter it in the console as a stopgap measure to keep playing with the uncommon quality unlocked