Floor Pppu....where In The Pu Progression?

A floor version of PPPU isn't in the BtGB book. Where would it fall in the order of pushup progressions? Seems like it would go between XR pushups and XR PPPU? Or does the instability of the rings make XR pushups technically harder than FX PPPU?

I'm pretty sure I've read this topic on the forum before, but I couldn't find anything when I did a search.

-Martin

I am far from an expert, but I think ring pu and floor pppu nearly at the same level. I usually alternate between them from training to training. (I hope I do proper pppu). Ring pu is better, if one has elbow or wrist issues. (according to my experience)