On some Boeings, the flap will trigger the GPWS Mode IV, and it won't be cancellable. As stated, depends if the flap is defined as a landing flap config. If there are hydraulic issues, it can be a bad idea, as Ansett found on a B743 at SYD, which did a 16 point landing, which saved on brakes and TR wear, not so much for the NLG doors. The plane had an engine out and the related ADHP was low output, so the uplock pressure to release got messed with every time it got close to releasing the uplock. The crew under some stress were confumbulatorised bigly, and rationalised the red gear light with the number of gear lights on the engineer's panel. 4/4 instead of 5/5... oops.