Had a feeling that FULL = FLAP 40 was an A319 thing, not an IAE thing. Think the IAE maximum nacelle-diameter may be smaller than CFM, aulglarse, but bigger at the aft end 'cos of the full-length fan-duct.
Interesting that FULL gives so much less FLAP on the A321 than on the A320, apparently. Guess it might be the higher wing-loading? [A321 wing is same area as the others, I believe.]
Good question, Sam...