[ocelotpotpie]

(Disclaimer: I'm on the Paper team, and Paper is the org under which Folia sits.)

Paper (and Folia) have differences from "vanilla" (official) Minecraft, which is part of how they improve performance to begin with.

So it is true that there are differences from vanilla. Most "in-game devices" - if you mean builds, redstone machines, mob farms, etc - have versions that people have found will work on Paper and Folia. They might require some tweaking but complex redstone and mob farms are definitely very doable.

The goal is to have a close-to-vanilla experience while fixing bugs, patching exploits, and improving performance to run more people on a given piece of server hardware.

The biggest issue with Folia right now is that it's very new so there aren't a lot of plugins that support it just yet. That's changing every day! And of course it still has some crashing issues because it's still in development. :)