Multi-Orifice Flow Control valve location

snugone

I have a Peerless WB-3 with a 5 gpm tankless coil. The boiler was installed around 1993. There's a Watts P3 Flow Control valve on the incoming cold line, which may have been installed sometime later because the soldering work immediately surrounding it looks different (ie sloppy). Both Watts and Peerless instruct (see images) the valve to be located directly before the intake on the coil after the fork to the tempering valve, but on this boiler the valve was installed before the cold pipe forks to the tempering valve, thus affecting flow to both and not just through the coil.
How important is the location of the valve and should I move the valve to the manufacturer's recommended location? I just don't want to move it if there's nothing particularly incorrect with its current placement.


And before it gets asked, yes this home suffers from poor pressure in the hot line. So much so that if an upstairs hot tap is opened, followed by a downstairs one, the upstairs tap flow completely goes away. Completely. I think the upstairs tap starts pulling in air at that point.