This is a really awesome tool! For longer distances it gives way better routes than other tools I've tried
One thing I noticed in my town is that the the map isn't populating routes using lines tagged with 'path' or 'foot path' from OSM. For example, it doesn't populate the route I bike to work, and instead gives you a very steep and longer route despite the shorter and flatter route I bike being mapped in OSM. You can't force it onto those sections either.
Maybe you could add options as for what type of path/roadway the program will route you over such as including paths, or excluding highways?