This mod is an absolute gem, i really hope it becomes "complete" one day, or that there is some way in a future patch to only use the new (if still few) planet graphics.
I suppose one workaround would be to copy a planet 8 times or so and give each copy a different number, causing the game to load it more often. But meh
I do however find some not-gems among these planets, mainly the green/purple continent planets, i like the color difference and detail, but they are too dark, lacking highlight and looking rather flat. I blame the celestia mod creators, not you however

By the way, have you thought about taking one planet and mirroring it and like, using the clone brush tool to copy/paste a few continents or islands around, making multiple unique copies of the same planet? Perhaps thats the only logical way to fill up all the "numbers".