No special techniques. Pull a good vacuum before injecting. Keep the collection pot cold during flooding and no more than about 110F on recovery.
A Mk III has a dip tube, so can't be inverted to re-flood.
Hard to reliably make cotton candy without a view port in the lid, so as to see the exact timing of "now", where you switch from recovery to high vacuum and inflate the puddle. With active you can watch the ice ring for clues, but with passive there isn't one.
You can compensate some by weighing, guessing, and starting the high vacuum slightly early, which means you need a vacuum pump suitable for pumping LPG vapors. We used a Vaccon venturi vacuum on the WolfWurx Terpenators and discharged into the ventilation system.
When making cotton candy it is necessary to drop the collection temperature below about ~85F, which dramatically slows down passive recovery, unless you also drop the recovery tank temperature using something like a dry ice and alcohol bath.