Unimplemented type for cast (MULTIPOLYGON WKB_BLOB -> POLYGON_2D)

[marklit]

Is there a timeline for when casts like the following will be supported?

SELECT ST_GEOMFROMWKB(a.geom) geom2, b.*
FROM st_read('geom_xaa.gpkg') a
LEFT JOIN us_geom b
    ON ST_WITHIN(ST_Centroid(ST_GEOMFROMWKB(a.geom))::POINT_2D,
                 b.geom::POLYGON_2D)
limit 1;

Error: Conversion Error: Unimplemented type for cast (WKB_BLOB -> POLYGON_2D)

SELECT ST_GEOMFROMWKB(a.geom) geom2, b.*
FROM st_read('geom_xaa.gpkg') a
LEFT JOIN us_geom b ON ST_WITHIN(ST_Centroid(ST_GEOMFROMWKB(a.geom)), 
                                 ST_GEOMFROMWKB(b.geom))
limit 1;

Error: Not implemented Error: Geometry type not supported