We've had a request for recording the footprint area in the main source catalogs (so they can be accessed without reading in the full footprints, which is slow), which can easily be done with a trivial pure-Python plugin. This would also have been very convenient on DM-9962, so I think it's a good idea for LSST (even if it's too late for that particular ticket).

This will not be going in the next HSC release (it's too late for that), but we'd like to get it done before the next one in Fall 2017.