After now 2 month of discussion and developement I want to give a (positive) feedback.

I tried the new version now with two longer biking routes .... and navigation along a route works (almost) perfect.

I planed the route within route planer /brouter ... included some caches ... choosed my biking profile ... and the fun could start.
I was a little scared

when I saw the first deviation ... but all worked well.

Some missed turns by me leads to some further deviations ... but more or less I found back to my route without stoping on every second parking place.

Thx for your work and patience .... today for me it was great fun just to ride and get guided by Locus.

Within those deviations I saw that it really wouldn't help if you recalculate to much (because I set my distance for recalculation to 40m) but ... I had a new idea:

The problem when you leave your planed route is that Locus leads you directly back from your current positon.
While walking this is no problem ... but with car or bike it's almost impossible.
Maybe it's better (when motorized movement) to navigate straight in the actual direction and look for a "allowed" turn.
Then it would be not such a stress to have no possible guidance (because turning on street is most time not possible) ...
The second advantage would be that if you decide to ignore this short turn ... the next possible turn is generated or maybe even a better route back is found. (That's very near to my car navigation).