One more thought to answer a question from your initial post... maybe someone else can chime in with more details:

If you lower the level of your new return, you're effectively changing how much water you need to drain when you winterize.. remember, you're supposed to drain below your return outlet, so if you put one near the bottom of the pool, you'll have to drain almost all the water out, which weakens your pool structure in the winter.

If you're in a climate where you don't have to winterize, clearly this isn't a problem.. There may also be some sort of workaround if you live in a winter climate, but I can't think what it might be... some sort of patch to keep water out of the return fitting, I'd assume.