@paul69 regards your point 3)
a simple check I do is to check the total mileage for the trip is exactly as expected
to do this I include the total mileage in the trip name somewhere near the start of the file name
when I open the file, the planned mileage should equal the file name mileage
when I start the navigation & the route is recalculated, if all is well the mileage should still be same / correct
its not infallible as you could get a route change that adds mileage in one area, then a second route change that takes a shortcut & reduces mileage, so you end up with the 2 changes cancelling each other out
however the odds on that are low & a mileage check should alert you to any signifiant deviations
an advantage of thi8s mileage check is it works across devices, no matter what navigation device you are using
if the mileages for the route do not match, at least reasonably closely, you know that the calculated route you are looking at is going to deviate somewhere along the path from the planned route
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