I see a lot of higher-end cross country skis now have an NIS mounting plate to enable the mounting of bindings without drilling any holes (and easy adjustment).
But why are the only NIS compatible bindings that I can find just for the regular NNN norm? What about SNS Profil and Pilot, and also NNN BC? Is there a technical issue here, or do is have to do with patents?
(I know you can just drill any binding onto a NIS-equipped ski.)
The first part of your question: "why non SNS bindings for NIS plates" seems to be purely a matter of proprietary systems and corporate competition. SNS is Solomon's baby, NIS is a collaborative between Fischer, Rossignol and Rottefella to make a truly Integrated System. Likely, Solomon is not allowed to integrated the NIS plate into their skis, so has little interest in making their bindings work on other's skis.
Rumors occasionally surface suggesting Solomon is working on their own adjustable system (that may or may not work with NIS) but to date, nothing has been produced.
As for NNN BC - since NIS and NNN share the same blood, it seems likely the lack of NIS BC bindings is due to structural reasons. BC bindings are tougher for the torque you find in typical Back-Country settings, and you'll probably want a ski that goes with it (wider, metal edges, etc). Also, perhaps the adjustable NIS plate couldn't handle truly BC type skiing (this is just conjecture).
