How to enable rerouting ('Use Map' mode), but avoid the "Calculating..." screen?

Hi everyone.

I recently bought a used Fenix 5+ and started experimenting with mapping.

I immediately realized that the' Use Map' option must be set in the Routing settings to enable the watch to reroute you as soon as you leave the preloaded course. As a hiker, I find rerouting crucial, as I might willingly or forcedly choose a different path.

However, this setting makes the loading of new courses incredibly slow (the infamous "Calculating..." screen).

I understand the difference between track-based and route-based courses (loads of points vs a few highlight points), but I don't understand how the former is conducive to insufferable waiting times. Besides, track-based courses are my standard way to produce courses for the watch (I use komoot, Garmin Connect as opposed to producing route-based courses in e.g. Garmin Explore.)

So questions:

Are you using Explore instead of all other tools (komoot, GC, Strava, GPX exported from wherever)?

Do you face this issue on your F5+? OR perhaps stronger watches (e.g. newer Fenix)?

Is there a solution?