mesa WONT warranty groove tube equipped amps

Talked with mesa today about warranty questions and according to the guy I spoke with mesa will not honor the warranty if you use groove tubes in a mesa amp. He said it didnt matter what grade groove tubes to be used. He was very specific and stated that both the preamp and power amp tubes need to be mesa tubes or the warranty will be void if you return the amp for service with any other tubes but mesa tubes installed in the amp.

Now Im not sure if this is true or not as many who answer calls are given only certain information and may not be in the loop. But this has me concerned as many have been taking this "groove tube" rumor as the gospel. So not Im not sure what to believe. Mind you I will be keeping my mesa tubes in a safe spot if I in fact need warranty work. I surely hope its not an issue that would blow a tube because if I send back a broken amp with perfect tubes that might look fishy. And I really dont want to be dishonest. Does anyone have solid proof that the groove tube product can be used without issues?

It's written in the manual...so...

You'll need to swap back to original tubes when you bring it back to the shop. That's what I had to do. What a pain in the neck.

Yeah its just there is this rumor on this board that someone started where they said they spoke with a mesa employee and that they said that the only other tubes that "Wont" void the mesa warranty is groove tubes and that they needed to be rated 4-7 medium category. That way people could experment with different tube tones and not hurt their warranty because those GT's would be within spec. Many took this as the gospel and bought GT tubes. Including me. Now I found out that that is not the case. It may still be the case depending on who gets your amp for warranty service but its better to be safe than sorry.

The rule I heard from mesa hollywood (John) a while back is this:

you can use any tubes you want however, if the power tube shorts and takes out a screen grid resistor, the warranty is now void (if you had non mesa tubes in the amp at the time). which they won't know if you swap in mesa tubes before you ship the amp to them for service anyways...