Possible? Macro broadcast for each slave to select a different target?

[MiRai]

I can set up an external macro on my keyboard that will then press tab once, use the keybind, then tab again and use the keybind...

...but it does the job with one main button press.

Just to be clear, if you're pressing a key one time and it's performing a sequence of key presses without additional input from you, then that's considered automation and is against the rules of the game.