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Don't know about Mesas (amps or their valves) But...
"We" found many modern valves had high grid current which means they could be prone to "runaway" in a fixed biased circuit. High GC does in any event indicate poor quality.
However, it was found that GC dropped by several 100% after about 2 hours "burning in" and even faster if the amp was thrashed on a soak test bench.
So my take would be, fit decent quality bottles and set the bias but check it every 15 minutes over the course of a couple of hours or so.
NB. It is useful to monitor mains or HT volts the while else you can be chasing your tail fiddling with the bias pot when HT wanders!
Dave.
I've never had any issues fitting any decent quality valves in any Mesa. The bias is set fairly conservatively on them so you're unlikely to find a set that's outside the usable range, but if the vendor offers a 'tested for Mesa' option it's best to go with that to be certain.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Ah! The information was imparted to me by the Great Man, I being but a lowly asstnt lab tech and knew my place! I seem to recall an unusually large number of KT88 "Purple Deaths" and they were searching for reasons. Poor QC in respect of valves and the reduction of collateral damage is one reason why most of the designs feature lower than normal grid leak values and low Z (ecc82) drivers in some cases.
I also had some EL84s that used to crackle for the first few hours of used.
Dave.
Again this should have been done at the factory / by the vendour.