Get spark bindings (certainly stiff) for your splitty needs and an extra set of pucks to throw on your non-split...thus saved from buying 2 sets of bindings.
That's a really good idea. I'd do it if I loved my Light Rails as much as I love my Cartels. Maybe when I get Sparks or something else I love more. I don't know if regular Voile pucks would work on a solid board though, since splits have such wide inserts. There are a couple of companies that have slider plates that will, though:
Kits and spare parts - *Splitboards Australia
Split to Solid Binding Pucks | Chair 2 Board Sports
Capita Charlie Slasher 154
Venture Storm 156