The old VC10 ('God Bless the Queen!') started shedding flap units at one stage. It had 5 big units each side, they must have been like single garage doors. Dropped a few of those around the world.
The difference between F25 and F30 was about 3 knots, and not a great deal less on landing roll. I always preferred sticking with what you know and doing F25 even if limiting- that way you can put it down more precisely which is more important than an unfamiliar attitude landing-IMO.