A M32R is the center of my home audio system and is on 24/7. I rarely remove the dust cover to use the mixer itself as a control surface. It measures just under normal human body temperature and stays at that temp all the time.
I'd thought of circulating air under the bottom of the mixer chassis. It's raised in a stand that leaves a "pie wedge" of space that's 9 inches at the back. I haven't done so as the temp seems moderate.
Is this thermal gain harmful to the mixer? shorten component life?
I would bet you are ok, if the temp is only what you say. None the less, if it were me I think I would take off the cover while in use. I would say of the 2 issues high dust exposure is way worse of an issue than T 98.6.