Here is a video showing how to convert an imported route into a saved route - just using the XT screen. The process is described above already but this is what it looks like on the screen.
Just an additional tool, and already described above. But to use this, all you need is your XT in your hand.
Someone (@JackBunce) reported that the sound was barely audible. I've boosted it somewhat in the link below. Thanks, Jack - I hadn't realised - it was loud enough on my PC amplified speakers ! I have extracted the soundtrack and boosted it - but it meant uploading a new video.
Version 2 - Louder Soundtrack
The Repeated U-Turn behaviour - for which I coined the term "RUT" (as in being stuck in one) is most likely to show itself if the route has recalculated, and you subsequently go off route.
Then rather than navigating to the next route point, it spots the closest point on the route it has just calculated - which is nearly always behind you, and takes you to that.
It never happens for routes that are created on the XT itself though - a discovery that I stumbled across while out testing and needed to rebuild a route at the side of the road. It then behaved perfectly. That led to the discovery by FrankB that there was a single flag and later that a route could be set to saved just using the XT screen.
That XT-in-hand-while-on-tour method is decibed in my dulcet tones below.
Just be aware that the XT needs to calculate a route from where you are now to the first point of the route - so if your route is on another continent, or or even a hundred miles away, you may want to leave this until the night before you set off.
Alternatively, you can turn the GPS receiver off (in the navigation menu), place a point on the map near to the start of your route (don't save it) and then use the XT scroll down menu on the left of the map to 'Set Location'.
One video, but it is in two sections.
1. Nobbling the route so that it is 'Saved' rather than 'Imported'
2. Loading the 'Saved' route and saying 'Go!'.
Step 2 starts at 2:40 ish.
Ps. the displayed coordinates are nowhere near where I live. I placed the bike in a random position in Yorkshire and set the bike at that position. Its probably in the middle of a field somewhere. !