Well I think I just found my first ever bad-out-of-the-box JJ/Tesla tube. I've been pulling my hair out trying to get this SMD Dr. Wattson from the May batch finished up, I re-built the circuit board from scratch twice, and nothing was working. I checked voltages on the tubes, and one was fine but the other was way off. I threw in a Psvane (the new ones for the June batch are here) and it fired right up, sounded great. So I pulled a different new JJ and it was fine.
I've seen mechanical failures in JJ where the glass envelope loses seal after being dropped or hit, but I think this is the first time I had a JJ 12AX7 that looked fine but wasn't. I feel betrayed. Psvane are more expensive than JJ/Tesla but still less than the newly-increased Russian tubes like Sovtek, EHX, Tung-Sol, etc. I know this is still a 0.1% fail rate in the time I've used JJ, but it makes Psvane start to look even more enticing long-term.
EDIT: Well I'll be. The other May pedal that had been giving me trouble, @NKBassman's Black Eye, had the exact same thing. Gutted it and rebuilt, no dice. Poked the tube socket, I was getting 7V where I was expecting 200V. Swapped the tube and good to go.