Thats also a good idea. I'm on the fence about running UV any longer than first 6 months to year so thats kinda why I haven't done anything serious with it. I only really set it up for cloudy phase on new upgrade and just been too lazy to take it down.I was thinking about that myself, I have a 24W green killing machine in sump, so instead of tweaking my return for max performance, you can just do that in-sump, makes servicing easier too since the return pump can stay online.
I could also easily plumb it into one of my returns since I split it.
You may want to dig into researching the green machine. I think I've seen a few threads on the impeller not being rated for saltwater and leaching wierd toxins and crashing a few tanks.