@Eric and @Greg, I just had an astounding discovery. On the back of Hegel H360, there is a tiny switch called USB A/B. It was set to A in my case, and I switched it to B. Voila! Now the MacOS recognizes it as a device up to 192kHz and DSD64, and I am now able to play DSD over DoP.
In the Hegel manual, there is absolutely no explanation of what this USB A/B switch is about. Furthermore, it is still unable to handle 384kHz/352kHz or DSD128. Since I don’t own any of these higher res files (there are not too many on the market anyways), it works fine for now, but it still contradicts published information (192/DSD128) on Hegel’s website. I will further verify this with Hegel.
Thanks for the prompt responses. Your support team is great!