After slaving away with more GTK+ learning, I've finished a promising new dialog for dhcpcd-gtk.
I've also spent a lot of time polishing it with nicer icons, messages and titles. Unlike the previous version, this dialog works fully! It's looking so good, I've just released dhcpcd-gtk into pkgsrc for your pleasure - enjoy 😃
I also ought to get off my lazy ass and get ebuilds for them into Gentoo - maybe someone can do it for me?