Canvas / tolerance around a line (gpx)

I’m trying to get routes from gpx files in a map via leaflet (+ extension) with wordpress.

User experience on laptop is fine but on a mobile the responsiveness for the lines is not great. Is there an option to increase the canvas (clickable area) around the gpx track?

I believe that with the general leafletjs code it is possible. However, I am rather new to this and don’t know how to do it with wordpress (if possible at all)
https://github.com/Leaflet/Leaflet/issues/2689

The page I need help with: [log in to see the link]