@amd in my case it worked quite straight forwards, but is a little buggy.
If the tile contains text for example, you aren't able to edit it when opened a saved file. Changing it to another text containing shape and back to the initial one helped me. It's a pity that there's no issue tracker for it. Moreover, there's a version on 'makeronline', unsure if it's the same file.
I did a test print in the meantime and recommend to choose not to small elevation-, and path-scale values.
There are still a few parameter that need to be adjusted, but I'm about to start a test print of this tile displaying a bike ride I did more than 10 years ago (~ 150 km in 2 days). The area shows 3 different countries and also the disgusting extent of coal mining in western Germany.
Now that I opened the 3D printing chapter, my next project will be creating some memories of runs in the form of map tiles. Mesh data will be generated using a Blender plugin to fetch altitude profiles for given GPX data. The tiles will act as a gift and I hope it will be as nice as the examples on the project's printables page:
https://www.printables.com/model/1242540-hiking-and-cycling-map-generator-trailprint3d-blen
To avoid creating an enormous amount of waste, I will stick to one fillament type and colour the prints using miniature paints.