[Cucco]

Also falcon heavy use the same fairing as falcon 9 which limits payload size for heavy

[mrtnmcc]

And don't forget New Glenn uses Methane which solves the coking problem for reusability. Coke buildup plagues Falcon more than people realize.

[cubefox]

I think some Falcon 9 lower stages have already been reused 30 times, which suggests coking is not a major problem.

[panick21_]

As part of DoD contract an extend size fairing for Falcon 9 has been developed. So yes there is a larger fairing, that Falcon Heavy can use.