About as cpu intensive as an "event" or variable change on a programing software. Each frequency(say, 51) is it's own little bit with two states, on and off. When an output(sender) turns on at the frequency of 51, the variable "logic 51" turns on, and the receivers tuned to 51 all turn on.That sounds stupid CPU intensive, having each receiver have to do something for each and every pulse, whereas the current version will only send the signal direct to the block it's paired to.
A better way to handle frequencies is that when ever an transceiver is toggled, have it loop through an array and toggle each one to the new status.