They seem to be for sale on Amazon already..
https://www.amazon.ca/AZLA-SednaEar...+Crystal&qid=1623387462&s=electronics&sr=1-12
I wish they wouldn't do the 3 sizes when I know only L will fit..
@tgx78 .. we should split a box.. I'll take the L you take the others.
I'm not sure if I am correct but just comparing the pictures the Crystals you linked are for TWS with a very shallow neck. The last picture posted by @ranfan looks to be a non TWS Crystal with more height and your typical longer neck. If this is the case I'd definitely be up for trying them! The only issue with xelastecs for me was them getting dirty quickly and being difficult to clean. The material in the Crystal can be cleaned with water according to their marketing.