Add the ability to hold your hand up when you have nothing in your hands, the same animation you use to hold up an item.
I wanna be able to point at things, wave and, dance; mainly to interact with other players that have the mod.

The only thing is that when you left-click you swing once in the air but should be able to just add a delay
both hands would be awesome tho :)

It says right on the page:

How does it work?
If Emotecraft isn't installed on the server, this mod connects to an external Emote Server to sync emotes in real time (via WebSocket, similar to the Velocity plugin).

I might be able to do something similar in the future without having to host custom backend stuff, will have to ask around a bit.

Issue: this is a clientside mod. So nothing can be synced between players. Either the empty hand is always up or down for everyone, no possibility to customize or have controls doing stuff that others can see.

Issue: this is a clientside mod. So nothing can be synced between players. Either the empty hand is always up or down for everyone, no possibility to customize or have controls doing stuff that others can see. <

That really sucks :(
I wonder if you can look at this mod and do something similar

right-click right hand goes up/left-click left hand goes up
should be able to spam both and point up and down like the item holding animation