@Hubert-Thoring
Hubert,
That sounds like a good strategy - but it is out of the scope of my question. Sorry for the confusion; I will try to clear it up.
The latest upgrade introduced a beautiful new map layer to the app. It is based on HERE, can be configured with three different "colour schemes" (Vulf, Wong, Dart) and six "editions" (Explore, Simplistic, Topo, etc.) and looks like this:

This new map layer, however, is available only for planning/editing routes with the "MRA Routeplanner".
When opening a route for viewing/browsing, on the other hand, we still have the traditional maps where I can pick one out of twelve (MyRoute-app Default, MyRoute-app Street, MyRoute-App Outdoor, HERE, TomTom). Looks like this:

So, we have entirely different maps within the myRoute-app for various purposes. That is quite unusual; all other planning apps I know of use identical map(s) throughout the app.
My question is: Will the "traditional" and "new" maps be harmonised within the myRoute app, or are different maps for separate tasks part of a design concept?
(And to cover this as well: Yes, we still have one HERE "map" in terms of a "routing engine" that is responsible for calculating a route - but this is a different story.)