As an alternative to GPX uploads it is now also possible to uploaed saved Umap maps and render the contents as an overlay.
The visual results are not perfect yet, especially when it comes to marker positioning, and rendering symbols within markers, further improvements are upcoming over the next week or two, but current results are already promising and somewhat usable.
Example 1:
Example 2:
https://umap.openstreetmap.fr/en/map/icontest_199627
I ‘ve got an error importing data into maposmatic from this umap map : https://umap.openstreetmap.fr/fr/map/iti-cs_230446#12/48.7603/2.2536
In step 1, impor seems successfull but when rendering error I got an error for instance :
https://maposmatic.osm-baustelle.de/maps/23533
sorry, this is the rigth link for a maposmatic map with an error : https://maposmatic.osm-baustelle.de/maps/23527