This is really an old topic which is still an issue for me and, as yet, not resolved. I am reviving it in the hope that, since last raised, someone may now have relevant experience.
I am expecting an Arvus Atmos decoder with AES67 which I want to input via their updated Merging ASIO Driver (MAD) into the latest version of JRiver while also sending the output from JRiver via MAD to a Merging Hapi DAC. I am currently able to do the latter (output from JRiver) but, as yet, no one here has had success with adding the former (simultaneous input to JRiver).
I have had verbal assurance from Merging that, with the latest version of Merging's ASIO driver (MAD), simultaneous I/O is possible.
Anyone out there have recent experience with this?