I set the handle horizontal with the handle to the right. That fixed the Polaris problem but no water is coming over the spa which is consistent with how I understood your explanation. So I should move the handle to vertical with the handle on the bottom?
If you have the handle horizontal at 0 all the water will flow to your return and none to your spillover as you discovered. If you want the spillover running all the time I would move the handle down slightly to 30 to 45 degrees and make the spillover as slow a trickle as satisfies you.
Running the spillover all the time causes your pG to rise due to the aeration created by the spillover. If that is what you like and you accept that tradeoff then keep the spillover flow as low as possible. Moving the handle vertical will give you maximum spillover flow.
You can enable the SPILLOVER mode on your EasyTouch, keep the handle horizontal, and program the times on the ET for the spillover to run. Running the spillover for 15 minutes in the morning and 15 minutes in the middle of the day is adequate to turnover the water in your spa and keep it fresh and chlorinated.
To answer your follow up to my second question, I have a 280 with a booster pump. I installed it September 2018. I've posted a larger version of the original picture that was too small. Does that show you what you need to see.
I can't see the plumbing behind the first line of pipes. I can;t see where the booster pump picks up the water or where the booster pump output pipe connects to.
You have a lot going on with your plumbing. You should label all of your pipes. Here is my guess:
Returns:
1 - ?
2 - spa fill
3/4 - pool main return
what is the green line plugged in next to 4?
5 - ?
6 - this the cleaner booster return?
7 - spa jets
Suction:
A/B/C - main drain & skimmer(s)?
D - spa suction
