It would be nice if one were able to hold down left/right click to rout many belts at once, rather than clicking on each belt individually.

(thanks for the wonderful mod. I believe it has the potential to become as popular as RSO was: maybe even implemented in the base game.)

Thanks for the idea! You made a good point.

I wanted to achieve exactly same as your idea for multiple belts at the first place. Unfortunately, Factorio currently only supports modding API for custom user input that doesn't recognize dragging events. So the user input will only be trigger when you press down mouse button, but not after.

So for now, I guess there is no neat way of solving this problem :( Might have to wait for future versions to open this dragging support

Did you make an API request? If not you can do so here: "https://forums.factorio.com/viewforum.php?f=28". The devs are usually pretty generous with their additions.

Ohhh nice, thanks. Just add a new request.

Your request was added for 1.1:
https://forums.factorio.com/viewtopic.php?f=65&t=91098