Dear all,
happy to announce that provided solution from Dominik Hofer (PRO-JECT audio support Austria) works (bridge issue with ROON), and i am back with system version v.1.071 dated 1.10.2021.
Meanwhile, being on this version i have noticed that nither DoP nor Native DSD scenario in Volumio OEM settings works correctly with ROON, both converting to PCM. @john and @connor, any ideas?