I'm glad to hear your sprocket references. It's especially good to know you went back and forth and conclude the sprocket change is good. I would do that too, I think.
I mean, you've got the sprockets, why NOT experiment? No cost to do it yourself. I have to remember to order that thingy.
If they made it, I'd like to know if another tooth (16) difference would work. Seems like maybe they don't or they don''t fit. I'm alright with lower rpm.