51% is explicitly defined as consensus
Where is 51% defined as consensus? The whitepaper? Cite please!
No figures needed - voting with their feet is just simple majority - 51%
You could say it is implicit.OK boys, you two have fun getting your story straight.
And I expect it to be explicitly logically and linguistically consistent, not the hand-waving implicit wink-wink-nudge-nudge version.
PS Nobody else believes your preposterous "51% = consensus" falsehood.
Not even Garzik.

To roll out a change to the network you need to get most of the clients understanding both the old and the new protocol, and then when you have a majority you turn on the new protocol.
You just described a whole-network upgrade. I'd call that an incompatible change

The effort to raise the transaction rate limit is the same as the effort to change the fundamental nature of bitcoins: convince
the vast majority to upgrade.