I was intrigued by the use of a "suckback" event to cut off the dosing quickly and to eliminate possible quality issues.

Surely the best way to accomplish this would be to have a 3-way valve on the outlet of the dosing pumps close quickly and redirect the flow through the gear pump back to the source of the centrifugal pump feeding the header. A valve will close quicker than a gear pump can reverse direction and with much less turbulence and pressure variations in the system. This will result in a smoother operation with fewer failures.