It's a great system, but honestly, I don't think it's a good idea to add LV support, since it is a system that is still evolving. For instance, version 2 added point light volume support, which is incompatible with shaders that still uses version 1. If one day version 3+ gets released, all shaders might need to be updated again to support all the newly added features.

I believe those assets should have really simple shaders, and maybe have two variants like Standard/PBR and Toon shaded, that's it.