Unimplemented type for cast (MULTIPOLYGON WKB_BLOB -> POLYGON_2D)

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

```sql
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)
```

```sql
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
```