Yeah, looked into it briefly and yeah, if you put in a main drain it is just "safe" to run two of them...

But, yeah, I considered a couple of main drains, two returns and a single skimmer... Like you said I could always run multiples by teeing off at the pool itself...

So when I plumbed the equipment pad I have an extra line available for feeds and figure a single for returns is ideal...

So, if I put multiple returns in, how far apart should they be? I don't think they would need to be 180 degrees out from one another on a round pool...

I just got done with the plumbing... What a royal PITA... I only had a couple of tricky locations to really "work the angles" so to speak...

I did use a Jandy 3-way valve for heater select/bypass and Jandy check-valve by the filter, and for the heater back-flow I just used a gravity-based flap valve... I have a ball valve on the other side of it, so that I can positively shut-off the connection for servicing the heater.

I am sure if I did this kind of plumbing all the time it would have gone faster... I do now know why the pool builders use 1.5" PVC over 2"... It makes quite a bit of difference in pressure to hold 2" pipe into fittings compared to 1.5"... Enough to make me prefer working with 1.5" if possible...

But, now that all of that is done I can focus on everything else... I forgot to add-in the 2" ball valves for isolating the pad equipment, so once I add those in I will take some pics and post them...