If you can just convert to BVH that's the most generally applicable, then chop up your content into smaller packs so people can buy say 10 poses for $5 rather than having to get tons of them just to see if they work properly. Maybe add a note to say they're designed for Daz and let people customise to their own characters to save you any effort - really just a motion capture BVH is a good starting point for a lot of animations even if the feet go through the floor or whatever, you'll never make it perfectly robust for every figure, but you can at least make them broadly importable.