Hi.
All the VSL AU plugins don't work in Finale 27, here. I see them in Score Manager but they won't open when clicking on Edit Player...
Any other plugin, from Spitfire to UVI to Native (except for Reaktor 6) or Omnisphere, will show its GUI as expected, but Synchron Player, Vienna Ensemble Pro, VI Instruments Pro and so on will not.
I'm on a MacBook Pro M1 and Monterey OS, and I tried everything, including reinstalling Finale and rebooting my Mac.
Roberto