Oh yeah, no question, all of these machines have been high powered. At least 6-8 cores and at least 3.6 - 3.8 Ghz base speed, i7 or i9 or AMD "equivalent," and PCIe 4.0 M2 system drives.
To me the issues seem library / database based - in the sense of there’s something in the library that causes Roon to go off the rails on processor power at various times. As above, two possible culprits is high use of Roon Tags (which I do) and having unidentified albums (I have maybe 500). The process of identifying albums in Roon is really cumbersome, and for many it’s just impossible anyway.