You should be fine. We've had a couple of 6000s that rev up to full speed at idle but System Architect doesn't show them anywhere near thermal limit.. maybe 20%? Then we pound them. No thermal shutdowns, no thermal errors.
I'll have to put a sticker on them so I can follow more closely, but in the 15 months we've had our I-Techs, we've only sent in 2 for service (warranty) and that was for the sputtering, frying bacon sound on channel 2. That, apparently, is a ribbon cable issue. And we just bought 4 more...
We've taken the Sound Image approach: we send out *1* spare ITech with every rig. Just 1. So far I've never had to replace an amp at a gig, but I've used the spare to power a wedge for a VIP area several times.
With 3000+ hours, I'd say Arik's amp is broken in, not broken. If you're really concerned call Kevin Gring at Crown's Elkhart factory and get his opinion. He might have you run a couple of diagnostics before he can say "don't worry" or "send it in."
Have fun, good luck.
Tim Mc