The following packages are currently maintained by GNOME for no real reason other than they're a dependency of networkmanager:
net-misc/modemmanager net-libs/libmbim net-libs/libqmi net-libs/libqrtr-glib But I don't have any ability to test them. I'd really appreciate a dedicated maintainer take them over—someone who can actually test the packages. The packages appear to be in good shape. Recently-released versions have switched to meson, and I've made a PR here [0] for libmbim and libqmi. (In the same vein I wouldn't mind someone taking over NetworkManager...) Someone lighten my load, please? [0] https://github.com/gentoo/gentoo/pull/28163