I had thought that the recent implicit feedback changes were fully working on the BOSS GT-1, but it turns out that I just hadn't tested well enough. Audio playback and capture works, but with periodic dropouts. I get the exact same behavior as I did with the quirk to completely disable implicit feedback. Without the implicit feedback, you get dropouts from clock drift - how bad probably varies from card to card. On mine it is every second or so. If I switch playback feedback for the GT-1 to generic by doing "IMPLICIT_FB_GENERIC_DEV(0x0582, 0x01d6)", I get the previous old behavior, which is that playback completely fails to start. With generic playback feedback, and using my previous patch to endpoint.c to avoid playback waiting on capture mentioned here: https://mailman.alsa-project.org/pipermail/alsa-devel/2020-January/161951.html playback and capture work perfectly for me.
