I recommend a web server and writing a simple Java Servlet where you can push settings and then read them later. Note that it is still possible to encounter a race condition where one remote has read the value after another remote sets the same value.

If you only need on/off state and have an RFX9600, you can couple the relays of an RFX9600 to the power sense ports of the same extender and use that to maintain on/off or true/false state of up to 4 variables.

If it is just HVAC values, how about having each remote read from the same thermostat, etc... ???