Other interesting math is that C+F in this new A350 config occupy about 50% of the floor space on the aircraft at barely 20% of the 248 seats total.
C+F+E together occupy 2/3 of the floor space with only about 1/3 of the seats.
Which ever way you put it, it appears that Allegris C plus a fair amount of E seats just don't fit a F second row.
748 and 388 have more options, but these are not the bodies of the future and are not designated for Allegris or similar.
2 F rows worked fine on the 346/333 with a smaller and subpar C (2/2/2 config).
Quite a dilemma!