I've made some further very extensive tests in the meantime, but these were mostly for clearly GPU related stuff, i.e. the problem that the temperatures go through the roof when playing back any video. These were reported here: https://gitlab.freedesktop.org/drm/intel/-/issues/953#note_463451
But I haven't made any plots/conclusions for that new set of tests, yet (will keep this ticket updated once I've done). As for the general (I mean even when doing non-graphics intensive stuff like the unhide-brute or sha512 sum verify tests that I've described above) extreme temperature increase since >5.2 that I see, ... what I would try next is whether mitigations=off changes anything (it didn't for video playback). Also I found out about the nice features of perf record respectively perf report. I've played a bit with that already and the first "results" showed that when I do anyting (like just typing at the keyboard, quickly moving up/down in e.g. Evolutions mail list, or just Alt-Tab-ing between windows, the number of events recorded there increases by magnitudes(!!). I'd be thankful for any guide in what to actually test to better nail down that problem I see. Thanks!