hip mobility - should I supplement and/or modify?

hello

I am still using daily limber as my workout pre-stretch. I am unable to get into a APT hip position in both straddle and pike. My hip position falls into a PPT position (despite my muscles trying to do the APT). My hands are very near my hips. If I allow my low back to relax, and move hips into PPT and fully round my back, I can get my hands farther towards my feet.

In the butterfly, I can get my hips into APT, as well as get my elbows nearly to the floor.

What specific muscles might be causing this tightness? 

Should I be adding other stretches to my pre-workout warmup to improve and which ones?

Or will there be future mobility elements in Foundation One which will handle this?

Should I try adding a yoga block under my butt for those two stretches? 

HI Anthony there are exercise where PPT it is necessary and other exercise where APT it necessary.

JF it is an example where PPT is highly recommended while in the other IM's the more you can hold an APT the better tit is.

I think you care confusing APT with PPT. PPT means rounded back, APT straight back.

Thanks Alessandro

I did have those backwards...just edited the post to fix it

How about the other questions in my post?