Building polygons Coalesce

Hi,

I am trying to merge adjacent buildings.

I used --coalesce with --hilbert reordering.
Several buildings have been merged but most of them are still separated, even if they looks like to be adjacent.
It seems "coalesce" checks if two polygons are adjacent using the geoJSON geometry instead of the pixels coordinates zoom by zoom level. Isn't it?

Below screen shots show the buildings at the Z13 and Z16

Is there a way to set a "tolerance" to let coalesce merge polygons are not 100% geometrically adjacent?

Thanks for your help
Giorgio

Start by reproducing the reported behavior with --coalesce and --hilbert at zoom levels 13 and 16, using the adjacent building data described in the issue. Inspect the coalesce handling and determine whether adjacency is evaluated from GeoJSON geometry or pixel coordinates. Done means the desired tolerance behavior and its scope are clearly specified and verified.

Written by the indexing model from the issue text.