there's a huge difference free-revving a motor vs. throwing a load on the motor and running it to the governor. often, the governor cannot catch a free-revving motor.
I've never seen it. Sure, it'll go higher than it will loaded, but my Ford manual talks about a max unloaded RPM of 3800, for downshifting and such.
I... don't see that as hurting anything.
Also, remember, this isn't a gas motor or computer controlled motor. It's not going to 'free rev' very high beyond what the IP gives it, simply because it's fully mechanically driven - the flyweights are physically going to stop it within a short fraction of a second.
I've snap-revved multiple IDIs and they just rev right up and "hit a wall". I haven't ever had it rev higher, then drop down.
Also, pretty sure the motor can handle it. I only had problems with free-reving when I first got my RD2-110 pump which had the governor basically disabled; at 4500RPM I had a rocker stud wiggle loose. (Note: after that, I modified the pump with a proper governor again)
But that's a darned sight higher than the 3500-ish you'll get from a stock pump unloaded.