A single subscribed mod can now provide multiple builds targeting different game versions. This is tied to the existing branch system originally used for betas. Subscribers will be automatically given the mod build that matches their installed game version.

This means that when a player downgrades their game to an old version, they’ll automatically be switched to the last version of all subscribed mods that supported that version of the game.

This should save developers, mod authors, and players a huge headache due to not needing to worry about updates breaking everything (provided the developer has enabled and set up the relevant feature sets, which TBH looks a little fiddly).