Now I read this thread
I just sealed my Jacks Open backglass with TT. It was flaking in three spots - two flakes came off when I blew some dust and wood chips off it. Yes it was the red on a Gtb backglass and yes it was where globes are right on top of it so it was probably bound to happen.
I hope I did it right. Two pretty thin coats to start with and I made sure I went to the edges to try to seal them as well. Then I applied two thicker coats over the wear areas where the flakes were sticking up and I tried to get the TT in under them to seal them right up. Only time will tell I spose but for me, it was worth the risk and will have hopefully prolonged it's life. At least now I can touch up the bare areas over the TT with red glass paint and wipe it off if needs be.