Looking at the flights and seat map, looks like most of the seats are pay to upgrade for the extra legroom.

Is that what you mean with like 40% of the plan having extra legroom?

Options seem to be:

“Standard legroom (79 cm/31 in) Conveniently located in the front, directly behind the Economy Comfort zone Quick access to your seat during boarding”

Or

“Enjoy extra legroom (+10 cm/4 in) and recline (up to 5 cm/2 in) Be one of the first Economy Class passengers to board Conveniently located in the front of the Economy Class cabin”

Awesome, thanks.