@Craig-Nelson
Ofcourse you can pick a route from the library and modify it according to your wishes.
When adding a waypoint, you can drag and drop that waypoint to the road you want to drive on. And doing so, you must add or remove waypoints to change the route the way you like and avoid "strange and weird" reroutes.
It's much easier to start a new route and then, after selecting your startpoint, select the roads to want to drive on by adding waypoints on those roads. This will give you much more freedom to create your own routes instead of what i suggested above, editing a route from the library.
When creating your own route, you can add stop points for a break, lunch, nice views, etc.
All routes created in MRA are saved automatically into your own personal library to be found under your profile.
If you have the Garmin Zumo XT, you can use the Garmin Drive app on your mobile phone to transfer your routes onto youir XT or you can save the route to your computer, connect your XT to the computer and transfer the files directly onto your XT.