I guess it would depend on your
motor. Your drawing looks more like a double filtering system. It has to go threw (6) 3-way valves just to get to the
motor.
Mine would not take back pressure because the return lines between each injector are not clamped but just press-on hoses, which I've had to replace a couple times over the years due to seepage.
So, I would say it's up to your fuel line set up. If you had a leaking/open injector it may try to back flush into a cylinder.
How many hours on the motor?