I don't think Manoel is a long shot at all - as of right now, I would say he's a lock. He has virtually no competition at this point. While I haven't see Michael McKean, I can't imagine his performance will equal or even top Manoel's, but that's not the performer's fault, it's just the limitations of McKean's material.
At this point in the season, the only other person worth nominating is Christian Hoff from JERSEY BOYS. There are certainly no memorable or worthy male supporting roles in THE COLOR PURPLE.
Jim Dale, making his return to Broadway in just under ten years, might end up being a favorite though. We'll see.
"If you are going to do something, do it well. And leave something witchy."
-Charlie Manson