I think May is good here for grafting pawpaws. They need to be leafed out. It’s possible they could get scorched if grafting into summer, but I toss my grafted trees into shady conditions anyway.
I’m only just starting to get named varieties. Last year, my 2 favorites were Allegheny and KSU Chappell.
Maybe you mean “Tropical Treat”? I have this one, but no fruit yet. There’s a variety traded around on other forums called “Cherimoya West” that’s supposedly got cherimoya flavor. And an unreleased KSU variety referred to as “Piña Colada”. I hear Susquehanna is great, I haven’t tried it yet, KSU Chappell and Potomac are sometimes called similar and they’re both good. I only had a couple Overleese last year, maybe they’re first fruits and will change, but they weren’t particularly “tropically” tasting to my memory.
Generally, I find that freshly dropped pawpaws have a bit of a tropical vibe, but I actually prefer them counter ripened when they remind me more of a baked dessert.