Has Anyone Gotten Garritan's COMB2 Sound Library to Work with Dorico?

There’s no reason why it shouldn’t: there are templates for JABB and GPO5.

It’s “just” a question of setting up the Dorico instruments with the ARIA samples that you want to use; creating Expression Maps for mapping notation effects to MIDI, and then saving that as Endpoints for creating a Playback Template…!

I’d recommend looking through the documentation that I’ve produced to go with the GPO5 maps and templates here: