Those methods may help some, but I still think many are over thinking the use of a filter press. Don't worry so much over it.
As far as a bypass, I can't see how one would work well without the bypass. My first circulation thru the pump is 100% back to the mix tank just to be sure I didn't leave any clumps of DE. Then I open the ball valve to the filter and close the valve for recirculate. At this time all filtered syrup is flowing back into the mix tank. When the syrup looks like it sparkles, I open the bypass, close the filter and move my filtered syrup discharge hose to either my bottler or a SS barrel. I have an overflow set up for when a barrel is full, if filling a barrel, that either goes into another barrel or into the bottler. As I filter I watch the pressure gauge, and I keep the pressure at or under 40 psi. As the hollow plates start to get filled up the pressure starts to climb, I then slightly open the bypass valve. I repeat , opening the bypass more as needed (back into the mix tank) until the batch is all filtered or until I need to clean the press and start again, depending on how much I have to filter.
To plumb a gauge and a bypass into your press, at the pump outlet use a SS nipple, then a 4 way cross. You then have 3 ports to plumb, 1 to the filter, 1 to the gauge and 1 to the bypass. The bypass hose can simply be a vinyl braid re-enforced hose. The syrup hose is generally a high temperature silicone hose from the filter to where you will be sending the filtered syrup, and between the pump and the filter press it should be a medium pressure rated food grade hose, even though it should never really see high pressure, if it were to burst it could be very dangerous, spewing 180+F syrup around.
My press came with all of that plumbing (all I had to add was the bypass hose), but you can do it if needed. My press also had a bronze gear pump but after about 10-12 seasons it needed replacing or rebuilding. I chose to switch to an air diaphragm pump instead. Once changed I only wish I had started with an air diaphragm from the start, so much easier. First it does not need babysitting like a gear pump. I can just set the air pressure infeed at about 45 psi and the pressure does not ever exceed 40 out of the pump, so I can be attending the evaporator more. If the pump stops pumping I then go over and slightly open the bypass valve and go back to other chores. So much easier with an air diaphragm, but not absolutely necessary.