Leaflet Markecluster settings are lost upgrading from 1.2 to 1.3 version ... Store and reapply manually!

Leaflet Markecluster settings are being lost upgrading from 8.x-1.2 to 8.x-1.3 version, due to structural updates that needed to be implemented to the 'leaflet_markecluster' settings element, both in the Leaflet Map Formatter and Leaflet Map View style.
This mainly to prevent possibile interference of the previously named "map_markercluster" settings element, same as in the Geofield Map module.
Thus you are invited to store them before the upgrade, and reapply them manually, after it.
Sorry for that!