Matt, your back! I wuz afraid I'd scared you away with the {Painful but true} I'm better looking note. 
Back to your note; You know good and well I do get into the higher gears.
Problem is, I've been known to get into the higher gears, before I have much speed.
So {unlike you} I don't need top end POWER, as much as I need low end TORQUE!!
(PS: {Occasionally} I do have a wild hair and wind her up.)
On those rare occasions, I want some of your top end power...
Fais/Twin: Thank you for your notes. They are helping me refine my idea.Yes; I'm concerned with turbulence.
When the valve is closed and all the flow is going thru the single/right muffler, I think turbulence will develop inside the collector {at the bottom of the left port}.
As flow increases I think that turbulence will cause back pressure.
I have plans to smooth the flow across that area.
(** Not sure of details yet as I need the valve to determine that step, below is a partial explanation).
I'm hoping that when the valve opens,,,, that turbulence {and some of the total flow} will move out the left port.
I'm not particularly concerned with turbulence at the valve itself, because the flow
will be minimal. {If turbulence/pressure increases at the valve, it will adjust for it by opening more}. [I hope]

Attached is a Back Pressure video of an X pipe. View it and see the different flow characteristics at low and high flow.
The flow thru the collector and into the ports of this header are similar to an X pipe.
{on this header, the collector is divided into two separate tubes
by a dividing plate, and the flow exits thru 2 ports}
https://www.youtube.com/watch?v=Naq5Bcl7z-E** My plan is to smooth the flow by placing a plate at the "bottom" of the left port.
{That plate will direct flow to the right port and {somehow?} allow pressure and some flow to pass thru the plate when the valve opens}
Yes, I know I'm out of my mind.
But, I'm having fun.
Ride safe, Ted