Normally a group would have dimensions, this is partly true for PathCanvas groups, too. albeit, they only report coords when the group was moved.
Coords are skipped for the first version.
Example 4.48. ::vgcode::dump-configure-PathCanvas using pathgroup
... debug stdout "pathcanvas passed" } elseif { {group} == $type } { append _graphics \ [dumper::pathgroup $ta_name $id \ [dumper::itemproperties $optsl $id {} $target]]