Well, it didn’t take that much. I ported the small Qgis plugin to Qgis version 3.x. Luckily the renderer classes did not change, so the biggest thing to do was reorganize the code for PyQt5 and all the Qgis2 to Qgis3 API breaking changes. Just one coffee and a morning was enough :-).
It should be available from the qgis repository itself.