
I had a booster pump added in the initial plumbing to help with the water features and my 60" spillway.
The 2nd pump is a 2speed 2HP, and was originally plumbed to be spa only

Because the potential 4HP flow through the cartridge would have harmed it, they replumbed to the 2nd pump now just has a closed loop with the spa (non heated, non filtered)

Because of the check valve to the right of the main pump, the 2nd pump can only get water from the spa. It's return also only goes to the spa.
I have several other water features on the pool side that I'd like to power, and I'd also like to be able to get more push for the spillway. Currently at max power on the VS pump, the water is hitting the side mid face. It's cool, but I want it to sheer off.
Current setup:

I'm thinking about removing the check valve to the right of the VS pump, but I'd also need to adjust the actuator. Could I setup the GVA-24 for a 3 port, and close the spa suction so the spillway gets both pumps? I'd also like to be able to use the 2nd pump for the pool side. Where would be the best place for it to enter? After my SWG? Since there's a check valve after the 2nd pump, what's the purpose of the check valve in-between the 2 pumps (the one I want to disable)?