Open the Arteries on Water Pump to let it Flow!
I had similar disappointing water flow when using our water pump in the Landmark. It has a 5.7 GPM pump with sensor flow control, but it ran full throttle all the time and delivered poor pressure and volume in the kitchen. I made two modifications to our system: 1. Installed 2 gal accumulator tank, which also helped pressure at the kitchen sink and reduced pump run time; 2. installed a 90 degree elbow in the incoming source hose for the pump. In attached pictures (if it works) you can see the pinched hose going into the pump - this was an immediate problem - it forces the pump to work harder to get water through the constricted space, reducing it's effectiveness. No wonder it pumped hard all the time it was in use without good result. I asked someone from the factor about this at the Goshen Rally in June. He told me the pump manufacturer suggests using a soft hose to reduce noise when the pump is used.
Since these two modifications, we have great water pressure at all outlets, the pump runs so quiet that it is hardly noticeable. In fact, after putting in the elbow joint to open the pinched line, I had to crawl into the basement and listen to be sure the pump was actually working.
This may not be the solution you need. But I hope it helps.
Victor