That's what I had planned as well. Seems like a safe way to set it up. Can you connect the Versa to run with a photosensor with the Apex or Profilux? Like have the Versa always run when it's given power, then only give the pump power when you need to fill the ATO?I take a guesstament, and use that to add RO/DI water to my ATO. I add 2 gals daily to my ATO based on what I see my tank evaporate daily. I have to periodically add more water to the ATO thru Mobius, but, its not common. I will eventually add photo sensors to my ATO to monitor it more closely, but, found the other way almost as easy.
As far as the head pressure of the Versa, I have 2 installed in the basement, 1 floor below and have to pump it up a floor and thru, roughly 50-60 ft of 1/4 tubing. I have the RO/DI and AWC Supply Versa's in the basement.
Also, how strong is a float valve? I've never installed one and I know they're one of the most reliable safeties, but how much pressure can they block? If you automate your ATO, I would assume you would need to install one in your ATO in case the Versa accidentally got stuck on.