I took a look at the patents. The patent mentioned on the Allflex webpage (the publication is EP2285457B1) is a granted EPO patent with claims that are directed to . . . a plate for skis. The priority document for the patent was filed in 2008. There is no mention of snowboards in the patent. The claims specify mounting on a ski - "1. A platform for mounting a ski binding (71) to a ski (5) consisting of a fixing assembly (1) which is comprised of at least a base plate (11), which is adapted to be fixed to the upper surface (50) of the ski (5) in each selected area for the fixing of the ski binding (7), and said fixing assembly (1) is adapted to receive and hold a ski boot (6) in the desired position of the intended front assembly (71) and the rear assembly (72) of the ski binding (7), characterized in that the base plate (11) is elastically deformable . . . ." Features 71 and 72 are clearly the toe and heel pieces of standard ski bindings. Don't know if this link will work:
It may be open to discussion whether a snowboard can be considered to be a ski within the terms of the patent claim.
Allflex has filed a new patent application on the spring plate (PCT Publ. 2018169494) which specifically references snowboards.