Agreed - there is no one stop solution.
That said, I feel a lot better going with -
- a thermister (and I still think the CL90 is our best bet due to the warmup characteristics even with it's lower amp rating
- an inline GFCI to prevent the hot starts you mentioned on a power blip
- the rectifier diode mod
- a properly tuned amp
Worst case scenario, a variac run inline to drop the power if it's high average. I did find that it can take quite a while for those to stabilize, so best bet would be to leave it on constantly. And worth repeating, if it's just a couple points high, the thermister once again never goes fully open, and will drop the voltage some, so you may just get away with that if it's on the low side of high.
Still on the fence about the bottle vs SS rectifier thing, as there's the issue of what they sound like. To each there own there, and if a bottle sounds better to you personally, well ... that's the most important part of the equation.
I still don't have a clue why the OP's having the problem he does, unless pure dumb luck pointed him to a bad batch of tubes. Even then, first step is to use something like the Kill-A-Watt to see exactly what the incoming power looks like. Maybe an upgrade in the neighborhood like I recently had when they switched out from 4k to 14k lines ...