I can't say I know anyone who has them or have any experience with them, but a short investigation shows that they actually DO have a patent on their suspension system that basically just has a suspension arm that presses against a bumper of some kind. I assume this is only on the "flex" model, the other models look extremely normal.
The inventor (and presumably the owner of Rundle Roller Skis is Alain Parent, former Canadian team coach.
You can read it here:
https://patents.google.com/patent/US9314687B2