I have to agree that it is possible to succesfully and harmlessly do a hover auto in the R22 from 10 feet - I've had it demonstrated to me by an instructor to show that it could be done.
Note - could be done, not _should_ be done.
CJ - fair enough, you can happily bring an R22 safely down from 15 feet. Whoop-de-doo. Hovering at 3-4 feet should be more than enough if you're teaching a student how to hover and are worried about dynamic rollover.
The old adage - "just because you can, doesn't mean you should" would apply here. I'd like to see you go back to the factory course and ask if they advocate hovering at 15 feet as a matter of course. I'd be very surprised if they said they did.
Thanks to the old fogies for their insight into the original question. Excellent stuff.