Check this out.
https://www.youtube.com/watch?v=-fGifscQHmE
Good work!
Seeing their DIY project made me want to bring universal bindings to this forum too, as a serious option.
OAC EA is a binding that can be taken seriously in XCd context, I am getting performance perfectly comparable to NNN BC and Alfa Guard. Yes, it is more fiddly and if looking for good performance & comfort it is not universal, 1 out of a hundred winter boots perhaps. My boots at the moment are Lemigo Grenlander with felt or "kartank" liner. They form very well between the straps and my feet, without uncomfortable pressure, so the binding itself gives a half of the sole/ankle support. Flexible sole with binding plate pivot makes them comfortable for XC, and the (small) lack of support compared to Guard is compensated by the feel which the instep strap (perhaps our ancestors had it right in the first place) gives for ball of foot control. Well, in firm/icy conditions Guard has a slight edge, but then I am not expecting downhill fun anyways. But, in powder, or good corn, I actually prefer Lemigo + OAC for downhill, at least what comes to feel. The boots do not mind the here all too common 20+cm of overflow or cold, and I, with odd feet, wear them happily 24/7 if need be (just switch liners and socks).
Not for everyone, just saying that if you have special needs, and are ready to put the required time and effort to make them work for you, these are not a joke!