Have you already hooked up a valve to the cold water pipe and seen that you can get the flow you want? It would be a shame to do all this just to get the same flow.
I am on a well and have realized that I need to make seasonal adjustment to the regulator to get flow and proper shut-off. If the toilet in the laundry room is filling, you can forget about substantial flow from the kitchen sink, too.
A little adjustment in the pressure from the pump should
make a correction. That may require a new/larger pump.
See my post “11”. Thanks.