Though this is a viable concern in the greeter, as Chris suggested, Lubuntu has been using SDDM for a while. There's no plans of adding new features, including this one, in the 18.04 LTS for Lubuntu. Sorry.
Though this is a viable concern in the greeter, as Chris suggested, Lubuntu has been using SDDM for a while. There's no plans of adding new features, including this one, in the 18.04 LTS for Lubuntu. Sorry.