I think the concern is connecting the two ports into each other on separate controllers. They will not be electrically isolated if you do that which can cause problems and maybe screw up the controllersWithout the specifics of an application im a bit stumped. If your just needing lets say a single float switch to send a n/o or n/c to two different apex's at the same time through a analog input ala 'break out box' on each apex then sure that wont be a problem. You would just split the float wiring and run a set to each apex. With the analog signal you just do your outlet programming to each apex as needed.