At Communiteq we’ve been running a gazillion multisites for over 10 years and I can only name a handful of plugins that had issues.
Most of those use GlobalSettings or ENV variables so there can be no distinction between the different forums. I know the OneSignal plugin used to (?) have issues with that. You have to configure the API key at the multisite master or it wouldn’t work.
Another one was the Discord bot plugin (because it uses a gem that spawns threads) but that has been fixed for sure.
Generally, you should be ok and it’s not something to worry about. The plugin API does a very good job at abstracting away the gory details of multisite.
Oh, and for theme components it’s never an issue.