I regularly use Placemark as a replacement for geojson.io - looking at, potentially editing, then re-exporting some piece of GIS data.

For instance, importing a shapefile, renaming a column, and exporting as geojson.

For that use case, I don't need the map to be saved to my collection. In fact, I'd prefer if it was a temporary file than an extra item polluting my list of maps.

Maybe all I'm asking is a mode accessible from the logged-in state, for instance at the same place where the "new map from clipboard" option resides.

In this logged-in play mode, an option to save in the collection might be useful.