Line Array Adapters for Compression Drivers

specifically for 1.4" throat

for example this one:

https://www.beyma.com/speakers/Fichas_Tecnicas/beyma-speakers-data-sheet-horn-SG6.pdf

is twice the price of this:

https://eminence.com/collections/waveguides-and-horn-flares/products/la_wg14#specifications

but is it actually better ?

i noticed they use a different scale on the chart. if the charts are to be believed then Beyma is better - but why ?

and why can't they use a normal V-Dosc. is it patented still ? or is there some kind of issue with that design ?