Right now there's the functionality in place to put nearly every type of object on a bar, but blizzard in Legion made it so you could put pet buttons on your action bars. We should add this in as well

This code should be added to the rest of the "MACRO_Place****" functions in Neuron-Buttons.lua (these start on line 1945)

Just an FYI that you can't drag but you can manually add a /cast macro to an action bar button and it's handled the same way that other abilities are (for instance, disappearing (sorta, leaves a border) when the pet isn't active).

Yep, I looked into this today, and because of the limitations of GetCursorInfo() this won't be possible