The Raku Community Modules Adoption Center (tagline: "A place where abandoned Raku modules are being kept alive") seems like it would be a good source for potential _ sub-packages.
It currently has 113 packages that are up for "adoption" and, from a quick scan, it looks like several might fit with _'s purpose. Many of them won't, of course – either because they're too big, they use dependencies (and can't be easily re-written not to), or just aren't utilities. But with 113, there are probably at least a few worth investigating.