When MRT and multipass are not supported, we fall back to sorted alpha-blending.  Isn't this going to look completely different than OIT?  What are our thoughts?  So what?

I wonder if we get OIT brightness saturation as best as we can and then leave sorted alpha-blending as is, and provide a flag to use or not use OIT (when available; default to true) so users that can't tolerate the saturation can decide on the tradeoff.