This is awesome, and I was strongly considering doing the same but for three issues. My buddies fabrication shop is on the other coast, my garage may as well be a cardboard box, and damage I would likely inflict. I think the first two make sense, I don't have 3000 mile arms. The rent to own situation on cardboard is awesome. I'll skip along to my thought process on the third.
I've torn a belt in the first months of riding, and skipped teeth on the second belt already. Full disclosure I'm almost 200 lbs and I greatly enjoy torque. I've bought some spare belts and brushed up on how to install them. I'm keeping the factory tension specs (not over tension). The way I see it is easier to replace belts than all of the bearings I'd cook by over tightening said belt.
The 16's use a keyway on the rotor shaft. In every motor I've built for more power those keyways were the Achilles heel. Snapping the key either messed up timing (not a problem for us) or allowed the shaft to spin free, ruining the fun. Often creating wonderful strings of four letter words when the break is discovered. The worst part was always trying to save the broken keyway and reassemble.
I'm afraid of maiming the rotor output shaft vs destroying the belt. Given I break everything I love I'm sticking to replacing belts at the moment. If in a few months time this swap yields no issues I'm probably jumping in. Hopefully at that point I'll at least have found a larger cardboard box to call a garage.
Please update with how throttle happy you are and if it goes well. By the way if you ride like a professional smooth on, careful braking and the like I'm sure you'll have no problems. I'm fully aware that riding like an excited monkey is my problem and it's possible that they didn't design for me. On the 2017s they seem to have figured out a little more of my side of their market base and adjusted both the motor output and delivery accordingly.