ClearTables doesn't currently handle old-style multipolygons, and it needs to.
Probably going to resolve this in common with OpenStreetMap Carto https://github.com/gravitystorm/openstreetmap-carto/issues/1504#issuecomment-265933958 to use common code, common tests, and get more eyes on the problem. ClearTables is easier to unit test, requires more mocks to test this functionality, and has few eyes reviewing it. OSM Carto is harder to unit test, doesn't require mocks, and has more visibility.
OpenStreetMap Carto no longer supports old-style MPs in version 4, so I've done the same with ClearTables. I'm resolving this as resolved instead of declined because the desire was to have old-style MPs handled like other software, and it was done when those expectations changed.