ogr2ogr: convert all closed ways to polygons?

I'm converting an extracted chunk of OSM data to GeoJSON. We can use GDL ogr2ogr commands like:

ogr2ogr -f GeoJSON tmp_lines.geojson tmp_osm-solar-withreferenced.pbf lines
ogr2ogr -f GeoJSON tmp_mpoly.geojson tmp_osm-solar-withreferenced.pbf multipolygons

By default, ogr2ogr doesn't automatically convert all closed ways into polygons, only ones with certain tags which can be defined in osmconf.ini. The default is:

closed_ways_are_polygons=aeroway,amenity,boundary,building,craft,geological,historic,landuse,leisure,military,natural,office,place,shop,sport,tourism,highway=platform,public_transport=platform

How can I tell ogr2ogr that I want ALL closed ways to be treated as polygons? I know it's not always advisable in general, but in my case it's what I want, and especially I want un-tagged ways to handled like this. The closed_ways_are_polygons flag only seems to accept an explicit list.