From a personal perspective I am not a fan of anything that looks like a microtransaction or other chargeable piecemeal content; I would hazard a guess that Larian might curate some of the more popular user-made mods as has happened with DOS2.
I definitely don't like anything at all about microtransactions. But I don't see potential modules that way (such as being able to buy equipment would be). D&D has rulebooks (i.e the toolset) and modules. So why not BG3 and official modules too?