Here is a typical 3X tank. If my coolant level is the red area, please explain how air at the top of the reservoir will get sucked down almost 12" into the outlet tube and into the intercooler system? I think the real problem is the reduced i.d. of the inlet which probably produced more agitation in the smaller OEM reservoir tank. Did Ford change the size of the tank? No, they carried over the old unit and added a less restrictive by-pass hose. Super high technology there.It is more of a mixing air into the coolant that is the issue, attempting to minimize that was the bypass. When both air and coolant are in the same tank and all coolant flow is also through that same tank, and agitation of that coolant in that tank with the degas air..........well, you can see the picture from there.....
Where ever the degas tank is in the system flow, air/coolant mixing can occur, of course the degas tank is at a higher point in the system to perform the degas function.
Even small air bubbles attaching to metal in the cooling system cause "Hot Spots". Most all of the coolant additives are designed to help minimize Hot Spots and minimizing the air/coolant mix to start with also minimizes Hot Spots.
It seems to me that going backwards from the SVT Engineer designed 2013/14 bypass system defeats the purpose of a better S/C cooling system. If the 2007-2012 S/C cooling system was good enough, they (Ford/SVT) would not have spent the R&D $$$$ on improving it and then the production change costs also.
If you think putting a bigger pump in the 13-14 and then running it at half capacity with insufficient wire size for the load is an engineering marvel, I guess I just don't get it. Ford designed a system that could handle 12 psi of boost and then programmed the car to pull 3* of timing at IAT2 temps of 125* and 6* by 150*. When you're raising boost by as much as 50%, your intercooler system is no longer capable of doing the job it was intended to do. Maybe I am going backwards, but I think that remains to be seen.