tldr but my home planet, while not a "colony" was customized by myself and my daughter. i paid a visit less than 24 hours ago and it looks like someone looted the place, beds, boxes, even the plants were gone, but the structures we made were intact as well as some trees we planted.
Maybe you could see about getting a copy and have a file on a private server or singleplayer to keep it in different locations so even if it's griefed your work can still last.... However I don't know how true this can be, I heard about it from someone in the server, but I have little experience in this and have had minimal contact with the server mods/admin about it. I'm sure they're busy but just to entertain the thought when they have time.... Or you could do a side project in singleplayer/private server with your daughter so you don't have to worry about impending griefers! *EDIT* Would be good to message the mods/admin about this.
Sorry, guess I should have expounded. I read the first page of this thread and was just adding my $.02. It sounds like things keep getting auto-reset to "factory default" as it were and I was just trying to say that my home planet was modified before these problems started happening and is "fine". I don't need anything done about it.