Stally,
I've worked at two operators using Airbus, and neither of them use INT continually during push back/engine start. There can be a lot of operational chatter going on that the dispatcher doesn't need to know (monitor the engine start yes, but it's full FADEC. If anything happens you still don't touch it anyway). And most dispatchers I've dealt with wouldn't have a clue what you're talking about even if they could here it all. Especially in Asia where they'd think you have a problem if you started using non-standard phrases etc.
I see what you're saying, but I think it'd create more problems than it'd solve.
morno