I see, so many variables it's impossible ot know for sure what is to blame. Same amplifier, same firmware of the usb input of the amp, same cable, same usb port etc. only thing that changed that caused this frequent instability is the update to ventura beta 2 or 3 i'm unsure which as I haven't listened to music a lot the last few weeks when I updated the machine.
When both integer and exclusive is disabled, jriver still requests sample rate change, this seems to sometimes fail for no reason and trying again it plays fine, but sometimes the error persists and it works again if i do a manual change to the sample rate of macos within the audio midi setup utility. If jriver encounters an error when requesting exclusive it seems to crash coreaudio and it hangs until coreaudiod is killed and jriver is forced closed and restarted, or reboot of the machine.
I'm not blaming jriver for any of this since all points to something with coreaudio in the newer updates, but there is some kind of issue with the handshake or what it's called as a result of an api change or something apple did and if this is not just a quirk on my specific install/hardware could be fixed if someone else is experiencing it in the coming weeks/months when others move on to that os version.
After even more testing I can till reproduce the coreaudio crash even if there is no sample rate change and that it is both sample rat change with jriver and the exclusive mode that is causing issues. I tried playing music on spotify while changing between all the available sample rates in the audio midi setup utility and there were no issues at all.
tl;dr when jriver requests exclusive mode and/or a different sample rate than currently being used by macos it either fails to play (sample rate) or crashes coreaudio (exclusive mode) so all other audio in macos is not playing and safari and all sorts of other programs are freaking out. Even when it fails my amplifier briefly reports the sample rate that fails to play back so it's really strange.
another edit: I've tested another high quality dac and it's the same, so ruling out any hardware issues