Any experience with Tube rolling 6922 for Conrad Johnson preamp?

I am running the stock 6922 in my Conrad Johnson ET7 series 1 preamp.  (If you are not familiar, the preamp uses a single 6922).  My dealer won’t discuss other tubes, encouraging me to only buy from CJ.

wondering if anyone can share their experiences rolling the 6922 in an ET7, other ET series, or even older CJ preamps.  Also wondering what brand of tubes CJ uses as stock - I have not yet removed the cover to see.

have created wonderful improvements with NOS tubes in other equipment, hoping to do the same here with the 6922.  Full disclosure-I have also laid some eggs, too.  Very expensive eggs.