Sean I wanted to check roon arc but of course I couldn't log in.
Harshness still will be there a bit, because I suspect roon uses one of the resample algorithms optimised for speed and energy efficiency. Still I believe much better than basic Android resampler.
As of Dudu, I suspect the AKM DSP is added after all Android processing, so one input, one output, instead of being a heart of every input and outputs (as per data sheet). That's why it's impossible to do what they claimed in the marketing gibberish. Poor design choice, but the cheapest one, take a standard complete FYT board and just add a DSP before amps.