Then, to load up to the certified MTOW and set off for Bongobongo is very naughty.
That's true but it's also not what Ryanair is being accused of and is completely irrelevant here, as ATOW is not what charges are actually based on (see the Eurocontrol FAQ for confirmation). If you declare a reduced MTOW and always have ATOW<RTOW then all is fine and dandy, until you also try and get en-route charges based on the RTOW instead of the structural, certified, absolute MTOW.
Ciao,
Dg800