I have exactly this NAS with 2 TB SSD M.2 & 2x4TB HDD. The NAS is a great gear and because of the missing fan a good companion.
However I had the Roon Core installed and it works fine (DSP was switched off) but only if you do not have too much other processes running. I am using qsirch to index my Files and and have some other tools in the background running.
Result: the cpu goes up to +90% and the os is slowing the cpu down to avoid overheating. I am pretty sure that the usage of DSP is not a go idea after my experience.
Do not get me wrong, it works, but the machine is on the edge and this does not give me a good feeling, because I store important stuff on it and I don’t want to blow it up due to overheating. Having a cpu degraded to 0,8 MHZ isn’t good either.
As a result bought a nucleus plus with ssd and use the NAS as backup for my Files, as download station and multimedia station for pictures and videos. The nucleus plus is doing fine with DSP for sometimes three endpoints.