I know that HotSpring offers a retrofit kit to install ACE systems on tubs going back a few years, which includes a separate control panel. I don't know if that is true for the Caldera tubs. (I
was a Caldera dealer but I am no longer one).
Also - if you are adding a third-party salt system, you should do your best to get lots of water flow through the cell. For me, that means putting it into the core of your filter, with the constant circ pump moving water over it.
And no, you will not be covered under warranty, IF the problem is CAUSED by this system. If you have a failure which is not in any way related to this system, you should still have coverage: Watkins is not looking for excuses to hang you out to dry. If you mess something up yourself with this system, be prepared to pay to fix it.
HTH