High-altitude autorotations?

Not terribly military, I know, but...the local TV channel's news
helicopter (a Bell Jet Ranger) and its pilot appeared in a commercial
in which the stated ceiling was 22,000 feet. I remarked to my
aircraftwise 8-year-old, "Twenty-two thousand feet? I wouldn't do
that!" When Joshua asked why, I explained about the difference
between helicopters and airplanes when it comes to gliding and
dead-stick landings.

And this got me wondering: Does anybody test to see how high up you
can successfully autorotate from? Is there an actual record for this?