Show a loading icon when plots are being loaded onto the map
Currently, on slow connections, a somewhat long delay can happen between the moment the user's browser requests new plots to be shown on the map and the moment they are actually displayed. This can create confusion for users, who may not know why plots aren't being displayed during this delay: is it because there are no plots to display, or because the connection is slow?
A solution to this could be to show somewhere on the interface a loading icon when plots are being loaded, to indicate to the user that something is happening and that plots will show up on the map eventually.