Good idea. I can do this.Since you're not glued together yet I'd put the outlet of the UV into the skimmer section to avoid bubbles. Or into your sock section.
I'm not sure if I'm understanding some of the suggestions above, I've never heard of anyone requiring all water go through your UV before going back to the display. That would require a huge unit in order for you to get the flow rate you need to your DT from the sump. Specially if you are actually trying to kill parasites with the dwell time. I'd think the wattage would be so large to meet that criteria it might over heat the tank.
I cannot plumb the UV into my return. My plumbing is soft and complicated as it was done 10 years ago by random people. It’s a custom built tank and some parts were not done professionally. A plumber I called told me I’m being too perfectionistic when I was just telling him exactly what people on this forum said to me.
I am treating for parasites with copper. I just want UV to make my water clear and maybe to kill any parasites. I would of course like to plumb it with the return, but I need to call a professional who…will actually do the job.
Until then, I’ll just dump it into the skimmer section. The water might get double processed, but that’s the best I can do at this point.