I;m not too sure if there is a mod limit, i know i must have 25 or something lol. It will take the mods you have a couple minutes to fully load in if you have a lot though. I also know when a mod gets updated it won't be read by it's save correctly, since the mod data has changed.

i have probably every single mod in the workshop turned on
there does seem to be some issues with how they are loaded though but i got a process that hasnt failed me

1. subscribe to everything in the workshop, cause why not
2. launch game, go to mod listings, turn on every mod
3. close game and reopen it
4. dont click anything. just sit at that black screen with the whatever warning text who actually reads anymore ANYWAYS sit there until you hear that sound kobolds make when they spawn
5. once you hear the kobold thump, enter to the main menu and everything should be appropriately loaded without much issue. other than the time it takes to load maybe

6. type out all this and then see when the discussion was posted and realize its over 2 weeks old .... well hopefully this would still help someone or you if you still have issues, either way