I know this isn’t really answering the OP, but...
Monster tube specs are great, and we all want them, but the rest of the package is just as important. I have a set of DTNVGs that have solid ~2300 FOM L3 tubes. Nothing special, but nothing to sneeze at either. I was never really impressed with them, so they got a total of about 3 hours of use in the first 12-18 months of ownership. After talking to a buddy who is a bit of a low-key legend, I sent them to him. He worked some mystical mojo and also installed a set of super rare, very expensive bespoke optics.
Night and day. I prefer these over 31A’s and another set of dual tubes with ~2700 FOM tubes installed.
So, if you put bare tubes in front of me, of course I’ll take the better specs. But inside a well-tuned system, tube specs only tell half the story. Since I buy my toys with the intent of using them, and not with an eye toward resale value, I’m less influenced amd impressed by bonkers FOM numbers than I used to be.