I don't know if I'd start with a Broadway production for this talented actor, but if a solid regional theater could mount a limited run just to see how it all goes, I could see it transferring -- if Mr. Newell feels comfy with it all.
When I saw him in ONCE ON THIS ISLAND he sounded freaking fantastic, but Asaka really doesn't have to sing anywhere NEAR as much as Effie needs to. I do think this is the kind of role, like Evita, where until you're doing it week after week for a few weeks do you really have a sense of how it feels in your own instrument, and how much vocal rest during the day you have to endure to stay healthy. I can absolutely see anyone saying, "yes, I COULD do that, but spending six months not talking all day is gonna be really annoying."
A benefit performance, Hollywood Bowl performance, etc would be a great start too. I'd pay good $$.