I don‘t know if this is useful to you map makers, and possibly you already know this, but I just noticed it is possible to show the images of https://www.opendatalapalma.es/ against the background of OpenStreetMap.

Thus, to view the current perimetro (perimetro_dron_21102021_1130h_norte) against the background of OSM, go to https://www.arcgis.com/home/webmap/viewer.html?url=https://services.arcgis.com/hkQNLKNeDVYBjvFE/ArcGIS/rest/services/perimetro_dron_21102021_1130h_norte/FeatureServer/0&source=sd and choose OpenStreetMap as background by clicking on the appropriate tile at top left in what says something like “Basic map” in whatever language you’re viewing this in. (This is immediately to the right of “Details”.)

(General path to this map: In the opendatalapalma.es map of your choice, click on 
“Show full details” (or some such, I’m translating from German here) – at left
→ “Show data source” – at bottom right
→ “View In:   ArcGIS.com Map” – at top
→ choose “Basic map” – at top left, to the right of “Details”)

I’d like to take this opportunity to thank all of you map makers for the diligent and painstaking work you’re doing here in constantly updating this horrible mess!