The decorations you unlock by scanning the loot dropped by King Dozer is not available in design mode. How ever you can see and place them in play mode but obviously this does nothing if you want them to remain a part of your playground.

I have a glitch or maybe it isn't a glitch but everything in the "into the abyss" update isn't in design mode at all.

I don't think they add new stuff to playgrounds mode until maybe the drop(s) after? Because there isn't even Phantom Quartz availible for you to place and mine.

yeah, i have not o lot to work with