This is certainly not impossible, but it should be noted that any model suggesting a "limited flapping" precursor needs to consider the potential for appropriately manipulating vorticity on the wing (and, in this case, rapidly increasing circulation and abruptly reducing it - otherwise, the animal loses more than it gains). I have yet to see this even whispered in the literature with regards to early birds, which is pretty concerning. Cheers, --Mike H.
By "increasing circulation", do you mean a downstroke or an upstroke or...?