There is NOTHING fragile about the R22 gear. In fact it is the only helicopter I have flown that can run on sideways at 30 knots and not damage anything (to a runway).
The only real variable different than other types is the rotor inertia. Set a minimum wind speed for practice touch-down autos and carefully oversee your student and there isn't really a problem, with 1 caveat. High density altitude resulting from temperature and humidity increase the wind required to provide a reasonable safety margin.
Do the autos dual only and to a hard surface (runway) and it works well. Where I'm working now the R22 and R44 are the only types we take to touchdown during recurrent flights. The turbines (B206, AS350, and HU50) are too expensive to ding if the auto isn't perfect. Not so the Robbie's, we can let the pilot have more lee-way in them.
And about the comment that any experienced pilot can do an auto; it takes a mindset to always be ready, and too many experienced pilots feel they can handle anything and stop preparing themselves mentally. Recurrent training regularly starts with a first auto that would have killed us both, and progresses from there.