newdigital,

:: I think the best you can do is to write your own server that is able to [send] signals, & not react on every incoming request for a state of a signal = clicking or requesting refresh every second... if your build indicator/EA is programmed to have an interval of checking/requesting every few seconds then people will know a way to tweak that option... the indicator/EA code has to be very simple... if the user/indicator/EA controls the requests of refreshing your server will be at no time flat lined, death, overload...

:: a very good solution that I see is keep open connections to the server, clients can only keep connection open & can not request anything... the server is in control of sending at the right time to the indicator/EA... it's the same how metatrader is working, if you open metatrader client it also wait till a price tick is coming in from the server & everything change at that moment, price change & indicators/EA's updating... if it was the other way around that metatrader client request every millisecond... the metatrader server will be for sure in overload in no time. ( that is why if a broker server goes offline, people have an hard time to log in, the procedure of logging in by the client is sending requests = hard to swallow for the server)

a quick note,
IN10TION