Well that’s why I’m asking here. You can “map <Mouse1> some_function” but there is no “pan” function. Mapping <Mouse1> to scroll (down) does not enable panning by dragging while holding down the button but just in moving the page one step down.
So it seems to me that it either requires multiple lines in the config or it isn’t supported at all. I wanted to ask here first before bothering the devs on github.