The PD looks more like just a modified 26800. So that's 4 wide 2 tall so 8 cells of 3400mAh 18650 = 27200 so they are playing safe calling it 26800. It is a 27W output.
The 26800 before it was 30W output made up of 3 ports each 3A max sharing 6A total, 5V. So they went backwards with USB-PD.
The input to the 26800 was 2x2A5V = 20A input but from the reviews is seems like the 26800 PD is only 15W input, again going backwards.
Or in other words, the PD is hardly a step forwards, more of sideways to slightly backward step. Where is gained is it took existing mature technology and modified it slightly to suit those wanting USB-PD. Oh and they charged about $23 more for it.
Caveat: I only know what Anker have written, I've not torn these apart.