“There are rules for VFR VMC flying which are to remain clear of cloud horizontally and vertically with published distances to have between you and cloud.”
The most common part of the spectrum is less than 140kn, up to 3000 ft, in sight of the surface and clear of cloud. You will notice that there is no published distance between you and cloud in this case. Assuming cloud base is 3001 ft, you will get two bands of aircraft. One will be at 2000 ft (some people always fly at this level and for my sake long may they continue) the other band will be just below cloud base. I will be at 2700 ish…
The problem with this is if you are descending in IMC without a RIS both you and the VFR guys have very little change to see and avoid. There is a strong case for only doing this with a RIS, but this would be very restrictive at a weekend.
Edited to add;
“I suspect it is very accurate in altitude less so in range.”
It cannot be more accurate than the encoder info which is +/-200 ft. A Glider is unlikly to throw away 400 ft of hard won energy unless it is very sure there is a risk.
Rod1