FWIW I was messing with this posture a few days back. It seems limited in that it does 1 (or 2 things) very well but other patterns require a posture shift which is awkward.
If I do a half step → whole step shape, or a whole step → whole step shape it is super comfy for both. It makes the tips of my index, middle and pinky finger all exactly in line with each other and there is no “reaching” at all. They are also just hovering right above the strings with no effort.
I’m horrible at combinations requiring index, ring and pinky, so I always opt for index middle ring or just reuse index middle pinky. From that above posture (OP posture) index middle ring is awkward, and that’s what I meant above about having to shift postures to get that shape to work.
Oddly, I can sort of do index ring pinky from this OP posture. I think, again, it’s because it positions my fingers so they are all at the same level. No matter what other posture I try that dreaded combo on, I always feel like my pinky has to stretch over when it’s that finger’s “turn” to play.