I certainly understand opportunity cost, but I’m not sure it’s manufacturer issue in this case. I’m using Roon all over my house, patio, and garage, but my main 2 listening positions are both connected via HDMI -
- Home Theater - Roon engineered NUC model → HDMI → Denon x3700h
- Office - Roon app → Nvidia card → HDMI → Anthem MRX-540
In both cases, I have severe issues (inconveniences really, let’s be realistic 
). And in both cases, I have multiple use cases humming along with no problem.
- In my HT I can run airplay, xbox, roku, apple tv, apple airport express, ps4, all without any audio distortion. I can run the receiver as a Roon endpoint, but I could have done without the NUC device if that was the plan. And I’m not sure I can play MCH over Airplay, haven’t tried.
- In my office I can run Media Player, iTunes, Spotify, Amazon Music, games, etc. all in parallel without any problems, but in order to play 2 channel audio with Roon, I have to disable surround sound to everything else temporarily to get it to work. As a result, I’ve taken to listening to iTunes because Roon is too much of a hassle.
So I get they can’t support every possible combination of hardware / software, but they do seem to be an outlier in compatibility… hopefully someone can shed some more light.
I’ll test out the Denon / Marantz theory next week.