Stews have their own scripts to work with globalblocks, and ocasionally, it is needed to block that IPs at meta. We can issue two block requests, but that would mean double as API queries. A parameter similar to what's already in Special:GlobalBlock would work well.
Customize query in gerrit
|mediawiki/extensions/GlobalBlocking||master||+29 -2||API: Add ability to also block local account when global blocking|