I think buds should not be frozen in contact with ambient atmosphere. GW recommended packing the tube before freezing so less air contacts the buds, but I think no air is better.
I've had success doing cyro temp live resin soak extractions in a homemade glove box thats been purged and filled with co2 before freezing the buds with dry ice/IPA. No air contacts the buds and forms ice, the water in the buds remains ice, and no ice builds up on the outside of the extraction container. You could also use a Schlenk line for the same purpose.
Distill and dry your butane, use thermometers to make sure temps at -40C. I never use any heat so the fresh frozen is always wax instead shatter due to all the terps. Its not light yellow like PHO, but definitely not dark either
Packing prior to freezing isn't an option unless you mean packing and refreezing. The bags are coming from their freezer to mine. I am, and have been distilling the pure tane N-tane I have been using. It's amazing how much stuff is still in a can of 99.99999% "pure" n-tane. I'm thinking maybe it's not cold enough, I am using an mt69 in a bucket of ice water between the recovery pump and the recovery tank/manifold, same with my recovery tank
Should I be packing the tube with material straight from the freezer and putting it back in the freezer with caps on for a time? Or straight connect it to the system and fill the cryo sleeve with di/ipa and letting it chill before filling it with solvent? I've always been able to make vibrant yellow tinted extracts from fresh frozen material via thermos soaks and letting them chill in a cooler full of dry ice, so this learning curve is definitely disappointing, but not surprising.
Really appreciate all the input thus far.