Diffuser help

I test fit a polyU diffuser before I have it painted, and it looks like the FI exhaust tips will sit ~3/4” inside of the diffuser. When FI installed their 14” touring kit, they said that it is already extended as much as it should be. I’m sure I can lower the tips a little by adjusting the hanger brackets, but I’m worried that the hot exhaust gasses will melt the diffuser. Do you think I have anything to worry about?

FYI, this is just a test fit, and the ends aren’t fully secured.