Watermaker output ratings

[Hoghead]

I am replacing my Little Wonder watermaker for a higher output yield and confused as to how manufactures rate the output of their systems and membranes

A Dow Filmtech SW30-4040 (4 x 40") has a recovery rate of 8%, max input of 16 USG/Min, 800 psi Max operating pressure, and an output of 1950 USG day
It is rated at 1950 USG/Day or 81.25 USG/Hr - presumably it is at max flow rate and max pressure

The same SW30 model but 4 x 21" membrane is only 4% efficient????
Output is naturally lower due to the smaller membrane

Filmtec RO Seawater Membrane Elements | Applied Membranes Inc.

Filmtec Dow Commercial Seawater Membrane Specifications | Applied Membranes Inc.

Given the 4 x 40 membrane, is the output not 8% of the input at 800 psi? IE 8% of 5 USG/Min = 24 USG/Hr
I have been quoted this membrane with an output of at 60 USG/Hr at 5 USG/Min - pressure unknown

It seems that the only variables are input flow and pressure.
What am I missing or how is output calculated at 5 USG/Min input at 800 psi on the various sized membranes?

I am aware of the effect on output with temperature and salinity