Sometimes it seems to know that the paths are not the best, and I really force it to take the path I choose instead of more convenient ones. So it only suggests the rugged paths when I insist it goes "there, but via there there and there". Generally I can make it through, and how overgrown a path is can change by the season, so it's a bit tricky. At one point in Italy though I ended up at a Via Ferrata, at which point I obviously had to turn back.
I have Street Complete installed, so I've started leaving notes using that whenever I notice any issues. And to make contributions now and then, of course. :)