So while not officially supported, my Denon AVRX-4000 has worked reliably with the Cynical Denon plugin for several years. I recently did a firmware upgrade and now, not so much.
Seems the first command out of Indigo works fine, and then subsequent commands are held up and executed later, if at all. I'm 99% sure this firmware upgrade is the problem, as things started misbehaving right after. The receiver functions as expected when controlled manually or with the Denon Remote, but not with Indigo.
So I'm wounding if anyone else has done the most recent firmware upgrade, and if anyone else is having problems.....