And I think OSM, rather than Stravr itself, is the root cause of my 'no road here' issue.
F'rinstance, yesterday my biggest hiccough was the road highlighted green. It simply doesn't exist. Maybe it once did. Or maybe some OSM contributor/prankster put it in by mistake or as a joke. But every route planning system based on OSM - including Komoot - will quite reasonably offer a route along it.
As you can see from the blue track, I went this way and that trying to find the way through. There isn't one. I found a LOT of mud, though. In the end I went back down and around the hill. Lost 20 min or so pissing about up there. (The blank line/'trail' just to the south doesn't exist, either.)
It's fairly obvious, in hindsight, from the satellite views, that there's no road. (Orange is the original plan; green, my track.)
Having hit upon the wheeze of importing things into Google Earth Pro, I'll be making more use of that tool in advance of explorer rides in future - with a special focus on sketchy shortcuts.
Likes: Gok and Karl