[Flux]

The only thing that's comfirmed is that they did one piece in front of the green screen in the CBeebies studio. It's certainly not confirmed how permanant that arrangement is.

Exactly this. They’ve always done sketches and skits using chroma key or backdrops in front of or away from the main space (even in the TVC/East Tower days) so this could well just be a small promo/sketch shoot. Until we actually see live (or new as live) continuity on screen we can’t be sure what their setup is.