Thanks @archmoj, that’s could be a good workaround for some use cases.
Nevertheless, to have real contours which don’t vanish or deform/merge when zooming in or out, I’ve made use of the folium package.
Funny enough, as of today they haven’t implemented a real proper filled contour plotting function either, but via matplotlib and other packages, it is possible to plot filled contours in folium accepting a small detour involving GeoJSON - format:
I hope this helps anyone who is in search for proper contour plots on interactive maps.
In the meanwhile, I also hope and suggest the plotly-team to implement a proper (filled) contour plot functionality.
Thanks in advance for consideration