Champion XP farming?

[Shakura Jolithion]

I've gotten far enough with my solo game champion that the last nebula I've encountered becomes an empty nebula (I focused on champion instead of usual expansion for this game), and am now wondering how I'm supposed to increase my champions level so I can try different unlocks. It seems like the only way I can still get XP, now that the nebulae are clear, is to go around wiping out various guard posts around the galaxy. Is there any other way to get XP outside of a nebula, or is my champion essentially maxed out on levels given that I need 30k xp to level and get maybe 100 from any given guardpost?
I'm also starting to progress in the Spire Campaign while figuring out what to do with my champion, and I noticed they have a journal entry about me having a champion... is there some way to unlock yet another nebula scenario after having done as many as possible prior to making any other progress in the game?

[TechSY730]

You can enable repetition of nebula scenarios for some extra XP instead of encountering blank nebulae, (there is some non-cheat chat command to do it, don't remember off the top of my head what is is) but there is indeed a finite amount of XP available for the champion in any given game.

[Toranth]

The command is "cmd:allow duplicate nebula scenarios", that you can type into the chat window to allow any nebulae beyond the 9th to use duplicate scenarios.  Storywise, they make no sense (since they are repeats) but they are rescaled to your current Champion level and hull, and will give the expected levels of XP.
This command does not count as a cheat, and you can use it without fear.