I've used them interchangeably for this type of thing. (UHMW and PTFE).
I've had difficulty finding the width and length I want in UHMW for the thinner material (1/32-1/16")...
I've seen the roll up childs-sleds... but those were about 3/16" thick and were generally HDPE or other. .
I don't know whether you are just being contrary or if things are really that different / special in Cali? In all my life I've never seen a Crazy Carpet that was 3/16" thick, Not even the Industrial Rescue "Skeds" are that thick and I was on an industrial rescue team for 20 plus years. They are 1/8" tops. There is no way a roll up kids sled would be made from that thick of material, the industrial "Skeds" are enough of a pain to un-roll and get the victim into it with two adults, there is no way a kid is going to get it un-rolled and usable, without getting hurt.
The Crazy Carpets that I have on hand are 0.030" Thick, 20" Wide, 38" Long, and an Alaska retail price sticker of $3.99. Woo Hoo! Perfect for the application! IMO
MH feel free to continue to be contrary if you so choose.
I'll now return the thread to the OP's Question for discussion.