Ok. Figured it out, thanks to another post on the forum. It requires you to run Logic in Rosetta, validate the plugin while in Rosetta mode, then you can Un-Rosetta it and run Logic in non-rosetta mode.
1. Close Logic. Install Native
2. Open up Applications folder, right click Logic, click Get Info, check Rosetta.
3. Open Logic, open plugin manager, rescan Native to validate. If it says "validated". Exit Logic.
4. Open Applications folder, right click logic, Get info, uncheck Rosetta.
5. Run Logic and verify plugin is still validated and works.
Note the I'm running the latest version of Big Sur as well, so this fix works on 11.4.
@vadar1