I guess it depends on how bad the pellets are with respect to moisture, etc... It seems that they would have to be pretty bad pellets.
I don't have the answer as I've never ran it that high for very long. However, one time I mistakenly put in stove temp mode when I normally run in room temp mode. I was burning NEWP on stove temp 5 and my thermostat reached about 93
before I switch to room temp mode. It was between 30-40
outside that day.
Other may want to chime in, but I don't want to bump this thread. Probably bets to start a new thread.