John,
Your return valve is right after your new salt cell...
I assume, you have this valve set to shut off any spa spillover... Is this true??
If so, you know that to get the spillover to work, this valve has to be open, at least some, to allow extra water to go to the spa, causing the spa to spillover..
If you added an actuator to this valve, then it would be in the position where it is now, when you did not want a spillover. When you did want a spillover, the actuator would open this valve and allow water to go to your spa..
If you plan to get an IntelliFlo3, you could also get the relay card, so you could use it as a timer.. (I think anyway..) Did you already have plans to use the relay card option for anything other than your salt cell??
Thanks,
Jim R.