Hi ask me how to handle with a large number of markers. This would indeed be recharged via JSON.
Is there an example of this?
To append markers to a clusterer, first you have to keep the id "addmarkers" returns, and use it in "to" property,
but there is no easy way to manage which markers had to be manually append or not, in the next version, you will be able to manage your own clusters (depending on the zoom for example) thanks to a "calculator",
this is not yet released, but soon