Originally Posted by N410DC

This is a good point. I think the 400' ceiling is exceeded virtually every weekend, at every AMA flying site in the country. It's not big "secret," and (as you said,) the FAA has never taken any action, or even complained about the activity. I don't think will ever make an issue about it, unless a modal aircraft endangers the safety of a full-scale aircraft. However, when/if this happens, there will certainly be hell to pay.