Outlet Placement on fabricated LLH

Hi all. My name is Bill W and I am a steamfitter and welder by trade. I have been a visitor for a while, but this is my first post.

I am currently designing and installing a hydronic system for radiant flooring in my home. The heart of the system is a Navien NCB 190/060H that I received as payment for some welding repairs, (the relevance here is this isn’t something I ordered, just what i have to work with).

My question pertains to the design of my low loss header which I am fabricating. Rather than use the prefabricated navien header or make one from copper, I am electing to fabricate one from 6” pipe with 4 1-1/2” Thread-o-lets for the HWS and HWR, and Boiler Supply and return loops. With regard to this, does the placement of the outlets on this generously sized header have any effect on hydraulic separation or other performance characteristics? Specifically should they be in-line or staggered, should the boiler side be on closer centers? I am opting to fabricate this because I can. I could make it from 3” K copper but 6” pipe adds some system volume as a buffer (close to 3 gallons) and I have a bunch of 6” stainless laying around. With regard to air removal, I have a spirovent microbubble that will be placed on the HWS after the LLH and before the circulator pump. I also have a Naviclean dirt separator that will be going on the suction side of the boiler.

If i did not already have the Spirovent and naviclean, which I bought, I would have just ponied up the extra couple bucks and bought a Caleffi hydraulic separator. But because I have these items I might as well use them.

Thank you for reading, and thank you in advance for the insight.