Master Pedestal and Wave Form

Hello
I'm on a GH5S
I have an in-body wave-form, and from what I can tell, master pedestal acts as a "floor" and "ceiling" for all information captured. Is this correct? I keep reading people say its to sync up different cameras that have different settings, however, when I fiddle with the levels, some interesting stuff shows up on wave-form.
When shooting HLG, I can adjust to around -13, and the lows of the wave form will hardline stop at just a touch above the bottom of the wave form profile. Basically my blacks get squeezed to prevent them from going underneath this line. The highs never go passed a certain point no matter what I change it to. -15 is right on the bottom, doesn't matter what ISO I'm at or anything, it won't go below that line. but my blacks obviously get pinched if my ISO is too low.
When shooting VLog-L, I can't change the pedestal. The floor that Vlog assumes on the wave form is much higher, and the ceiling lower.
This inclines me to think most of my information is being squeezed in a smaller range of DR.

When I shoot CineD, it can crash through the ceiling and the floor if I don't tailor the pedestal to the current environment. This seems to allow me to customize where I'm allocating information and there seems to be a greater span between the "floor" and the "ceiling" of the wave form, which appears to offer me more DR. I can tailor the pedestal to favor highlights or shadows depending on where I want more information,
I've read lots about Log-L and HLG and honestly they both seen inferior for DR when compared to CineD