Some newer type of regulator- rectifiers run full constantly, burn the overvoltage to ground to keep voltage within the range.
That will produce a lot of heat and stress the alternator windings. Horrible design!
So you have data on this.. I would think that bikes run a lower speeds won't be putting out all that much power and at upper RPMs you'll have air flow.
Do all regulators do this?
Back in 77 the shop I was in had a cb550K that had issues with the battery going dead. Bike was new and under warranty. Told the guy to keep the Rs up but all he did was putt around town. Still it went dead. Remounted the regulator (known issue), replaced the alternator and field windings. The Honda service rep was on this all the way. We eventually wired the field coil full on, removed the regulator and installed a shunt type regulator out of a CB360/400. The guy was happy. Don't know how long it lasted tho but they were standard 350s / 360s / 400s / 450 / 500T. HD had been using that method since alternator shovels in 1970s and 80s..
Alternators a basically a current source for power, not voltage.
Some of the better newer designs use SCRs to clamp the alternator output and reduce heat. Don't know if the newer aftermarket honda regs use this method. If they have the rectifier built in they might. In that case there may be more heat but probably not that much and lower RPM alternator performance can be significantly improved over the mechanical regulator that comes stock. The stock mechanical regulator really only 3 charge modes levels based on position of the contacts and it has to rely on springs, caps and resistances to do so.. Not knocking the device. It works but it is still older technology. Of course, you can have a newer design that, if poorly implemented, can cause issues.