CP, as BJJ pointed out, I´m a dinosaur with no clue, however what would you do in an airplane that has a MEMORY ITEM (so no choice there IF you follow CLs) that requires you to go from full flap (35°) to 15° even at short final?
Or does doing so not destabilize an approach? Say you have the engine fail at 50ft above minima and the mem item says flaps 15? you move the flaps and risk "dropping" to or below minima? or just deviate below GS which might force a G/A as well (granted , you`ll do that with the flaps in G/A position...)
OTOH the original q was regarding the flaps when plenty of RWY is there, when staying in 15 is probably the better choice, especially for a touch'n'go, albeit not (IMO) necessarly following the CL.
I personally am a fan of the idea that a pilot should be able to familiarize himself and cope with changes in pitch, control forces and power requirements associated with an egine failure and/or flap setting changes.
Even more so, when the pilot has no choice ("IF REQUIRED" - > and the RWY IS short) and he now faces something he did not train for at all.