Ok, quick testing done, very very much improved. I random played a playlist containing one MQA, one vanilla CD, one 96khz tune and one DSD64 tune and turned off all sample rate conversion in Roon.
Not once, after switching perhaps 50 times, did the old loud crack appear. A faint "tock" sound can be heard sometimes, but I also get the same faint sound when pressing pause and prev/next. I think I had the same on my old DAC also. And DSD and PCM have the correct channels now.
The DSD clicking sound is still left though, but Brian at Roon is looking into this. It might be Roon related, or DAC related, or just something specific with my setup.
I also tested the ASIO drivers, same result there for sample rate tests and channels.
I have one problem in ASIO and WASAPI though, but I had this in the old firmware as well. 700+ khz and DSD256 don't seem to work (cracks up completely with ASIO drivers). This might also be a setup problem for me (bad cables, etc). In WASAPI I can't even select those sample rates after Roon testes the DAC, so there is something that prevents the highest sample rates working.
Should I send the beta to "left channel" and "gahabana" so they also can test?