... lsst_visit, lsst_detector, lsst_tract, lsst_patch, lsst_band, and lsst_filter columns
gpdf, indeed, I assume we want to keep these, and they (and probably something else) can be added via simple configuration. One issue here is that extending the configuration which causes obscore table schema change will need some coordination, so we should try to guess everything that we need in advance.
re access_url variations
This is again a matter of configuration, but I also think that some aspects may be easier to handle on a TAP server side, or maybe in a special database view, which should be easier to modify compared to migrating the data in the table. I'll keep that in mind working on implementation.
Joining PPDB and obscore is, I think, a whole new requirement. I believe it implies that we need to either have the Registry on the same server as PPDB, or we need to replicate obscore table to PPDB server. We probably need to know more specifics about this to decide what we can do.