When Mode S was made made mandatory for Gliders in Holland, on good soaring days the number of returns swamped the SSR screens to the point the controllers couldn’t do there job effectively. So “mandatory glider transponder off zones” were quickly implemented..... Doh!
You really must be careful what you wish for and really think these things through. I pretty sure this finding put pay to the plans to the enforced Mode S for everybody. Self autonomous deconfliction, which everyone can see will be the way forward.