You're welcome,
@dadan
Too late now, as you have ordered the PFE. I thought you already had one. Anyway, the Plenty mouthpiece also fits fine with the stock hopper front end. But, I'm sure you will be trying glass soon with the PFE. I've tried quite a few hopper cooling ideas after reading this thread. Expensive F-Bomb, cheap short piece of silicone tubing, Crafty CU attached with FW3 glass, expensive but cool TiChillum, and lately a semi cheap bubbler -- you can see scuff line in pic of my PFE where it mates with a 14mm reducer on the bubbler, annoying scuff.
The silicone sleeves -- I cut one of the longer ones to 2cm, as that length allows two parts to mate. Put sleeve on Plenty mouthpiece first, then twist/push it onto the PFE. Helps to wet the inside of sleeve with saliva first.
This is only good for lips. Does squat for cooling. But, it's closer to the hopper ideal of a short vapor path.
Separated at birth:
Actually, a clever designer from Israel sells a grasshopper feeder. Must keep her well fed.