EDOT glass is notorious for flaking. In fact quite a lot of early videogame backglass will flake and lift if stored in humid or poor conditions.
Triple thick is used to fix where possible this issue or to prevent it from happening on good condition backglasses. I had never done this before so here goes..
So after a successful test on the flaked backglass (it didn't turn to ash..), I've just used my lunch hour to spray the good one.
I did three coats in total. Each coat consisting of one horizontal spray, one vertical, and then horizontal again.
First two coats 5 minutes apart and third coat 45 minutes later.
As luck would have it, it started raining as I put on the first coat so I had to pull the doors closed, however I recommend masking up even if there's sufficient air flow.
Wait till tomorrow now before touching it.