Ad, I was under the initial impression that once chilled, no certs could be cleared. Now I don't know the mechanics but look at FPFI, they have been chilled and certs are being cleared. There are others as well.
Obviously, one would need to go through a specialized clearing firm like Alpine, Scottsdale, etc. My understanding is the cost to chill to a non-chilled stock is $600 and a chilled stock is $1k+