It's certainly been interesting. I think I'm now pretty well informed about what CT does (and doesn't) do. Far better than I was before anyway, but still short of expert.
One thing I've noticed is that it definitely has a
personality. It tends to be a bit "skittish", like a nervous horse that shies at crisp packets imagining them to be lions. A couple of examples from a 33km test route that I created.
View attachment 724320
I don't understand the first one. Wickham Way is a quiet suburban road. Possibly 20 limit (I'm not sure) so I have no idea why it avoided that short stretch. (By the way the 10 is a distance marker not a via point. I haven't accidentally edited the route to do this. This is straight from the algorithm)
The second one I think I understand. There's a crossing on London Road with a pedestrian refuge in the centre. It's possible that the algorithm has interpreted it as a (very) short stretch of dual carriageway and pressed the "avoid at all costs" button.
Both would be easy to edit out on a second pass.