Thanks to all for your answers. To clarify I'm referring to the track points (the field trkpt
in the GPX file), not the route (or shaping or via points).
Currently I'm creating the route with MRA, export the GPX file and follow the track on OsmAnd, without the navigation function.
To show what I mean I've exported the GPX of the track with a long route, ~3,000 km (red polyline), and a very short one (black polyline) and I imported both in MRA tracklog.
Comparing the two files, the red curve has less track points compared to the black one in the same portion of the route (I assume a decimation is done before exporting the file):

Since I don't use any active navigation following the track is very difficult in cities.
There is a limit of 30,000 points during a GPX import due to uploading performance reason.
I am wondering if there is the same limitation during the export and if there is a way to avoid it. 30,000 points seem a small number of points to accurately represent a long route.