I am worried that itch.io users are going to miss out on mods which adapt the tileset they bought, because they're all locked in Steam (I know Meph is already planning one for Masterwork). That's an issue Kitfox will need to solve at some point. Perhaps just a tag which checks if the premium tileset exists in the users folder would work.
Just forbid the distribution of unmodified premium assets. The way tilesets are implemented is probably going to change with all the new functionality, so each tile might end up in a separate file. Using the mod would end up with a tile that doesn't match all your other tiles.
Quality control over mods via use of forums moderators could greenlight to get around this non-premium content distinction, i don't mean to be rude but it'd be a bit cheeky if Meph added Masterwork on as DLC (though for nessecity of being paid to do the spriting and possibly added sheen by Toady, i don't know know, then it'd really just be a art-pack)
The most popular content from the forums is likely to be the first thing people download for their steam edition anyway besides what they can organise themselves.
This discussion is getting quite lengthy, and has few questions to Toady in it. Should it maybe be moved to its own thread?
Yes i think it probably should
Its odd and im sure someone can pick up a similar question asked previously, would you ever support DLC for the steam version collaboratively as a 'add on' or 'technical polishing' of a mod? To provide a example, a popular mod like Masterwork utilises elements of the game through DFhack to incur the desired effect by reusing game assets or mechanics exploitatively on script command (teleportation etc), if you were to code over these, it would constitute besides what assets the mod creator can bring themselves like sprites to creating a premium package.