I had a look at this today again, and discovered the following:
- Click the 3-dot menu, choose Download KML
- You can even choose which category to download! Save the file and upload it into this website:
- after pressing "Convert" you can download the GPX file. This GPX file can be uploaded into the POI libraries as usual.
This makes @Jörgen his suggestion for this page very worthwhile!
I am saving the map into my favorites