Joe, I think Sunndays' answer is probably the best for you, get the poolbuster, or similar.
The problem is that the actuators are 'stupid' they don't know where they are w/ relation to the ports they control. You could go inside and reposition the 'stopper' to allow some flow from the spa, but as you noticed, the spa water will equalize to the pool's level when the system is off. You could manually make the actuator open the spa a bit when you're running the pool via the toggle switch on the actuator (flip it to the opposite side for a few seconds then put the toggle switch in the middle "OFF" position when the spa port is slightly open) but you'd have to remember to walk back over and put the switch back into it's original position before turning off the system.
A lot of people are 'not happy' when they come to realise that their cool, automatic new valves can only 'understand' 2 stopping positions

FWIW : when I have to clean one of the spillover spas I either turn on the 'full spa' mode and brush the debris to the suctions or use the pool's manual vac without the vac head on and direct the suction end of the hose to the debris.
If you need any more help with this, I'll tell you what I know