Yeah, relevel requests must be sent to the DM team. It’s not automatic either. Each is reviewed on a case by case basis. If people want to relevel to pick a new feat, it's usually approved, but they're not blanket relevels or remakes.
As for MacOS you’ll have to ask the Beamdog developers
Edit: To elaborate on the MacOS thing, I don't know if they released the .35 patch on it, if not then you won't see them. Considering the game is no longer officially supported, but is now only supported for free by some former developers/community members, I wouldn't expect them to adapt their patches for all platforms anymore (as far as I know the console versions are already very far behind).