I keep seeing people ask this is Discord. GSE is not “Input Broadcasting Software”. It’s a mod that is entirely contained within WoW’s allowed API and is limited by WoW’s rules for what a mod can do.
Corsair, GHub, Synapse, AHK, Punchkey etc ARE Input Broadcasting Software. This is not news and has been covered very extensively here: Bots, Botting and the thin grey line.
If you are concerned about how to spam a macro without using one of the above it is very simple. Bind your macro to your mouse wheel and scroll.