LKG is a legacy backup option for plugins. The problem with this folder however, is that if someone has All in One Migration, or some other backup plugin, if it stores in the plugin folder, it will copy over to this LKG folder causing bloat.
Additionally, from a security perspective, this folder has the potential of having old/outdated plugins, because the cp command is not "syncing" the plugins to the folder. Merely adding.
Tied to this issue: https://gitlab.gridpane.net/gridpane/server-scripts/issues/147
Assigned to you for review @dpock .