I do not know the Drivesmart 86 but the later Zumos all do something
different.
1. The 590 keeps everything as it was planned. Even changing Vias to
Shaping.
2. The 595 - if you use the Trip Planner App to change a
Via point to a
shaping point, it seems to place the new
shaping point further back on the route onto the fastest road between the previous route point and the next route point. It also gives it a
different name. So basically deletes the
Via Point and adds a new point on the fastest route.
3. The XT does the same as above. But it also does something else which is intriguing. If you press skip at any point during the route, then it behaves differently. If tou subsequently miss a turn to a route point (
via or
shaping) and it can see a way to the route ahead - it will take that route and remove the
shaping point from the route. The same happens with a
Via Point. There are some examples of this behaviour in number of short videos that I recorded and posted here:
https://www.zumouserforums.co.uk/app.php/ZXT-P200
4. The XT2 just ignores the presence of
shaping points if it is talking to the tread app. It reroutes the magenta line onto its preferred route and then moves the
shaping points onto it.
It has never been observed with routes created and sync'ed with the Tread App. But it seems to happen very often with routes from GPX files - if the Tread App is connected and running. It is as if the programmer is treating the
shaping points like the gpxx route point extensions (or ghost points). This doesn't happen to every single route point. But it
Imagine a situation where a programmer gets hold of the wrong end of the stick about something. THey pass on this skill to new programming recruits. Who then do the same thing. Misunderstand and add their own. I have absolutley no idea as to whether this situation could be used to describe the Garmin sitaution. I would be very surprised. But certainly, the odd behaviour seems to be getting odder with each new Zumo.
Or maybe it is all intentional and we are just stuck in the way that we want the stanav to work for us.
Like take us along the roads that we plotted please.