Shortstripper,
Please make no mistake, my only agenda here is to live long enough to collect my pension.
I have absolutely no objection to gliders in clouds, as long as I can avoid flying through the same cloud at the same height!
I too would reconsider my "collision avoidance plan", such as in my Coventry example, if I knew for certain there were gliders ahead and some of them might be in cloud. A radio call from just one of "the swarm" to ATC would be enough to alert everyone. So PLEASE do it!
BTW, I'm an ex glider pilot, too - that's where I began flying. Went solo at RAF Swanton Morley thirty four years ago.