Yes, you have a point there, but as you also can see in the data sheet,
if AP receives PoE power at 802.3af, then it will function as 3x3:3. This is the moment I dont get the point of so level PoE consumption.
So, at this moment, even though AP is idle, I dont believe that AP is fully functioning with this PoE level.
Based on what you say, I need to connect many users, for AP to consume more power and go beyond 15.4W in order to function fully, i.e. with 4x4:3 ?