Were it not for several rather intellegent posts made by your account on several threads I would assume you a troll.  Given your reputation I offer my thoughts.

What is this implied agreement?  Can one fairly assume that other miners know of this agreement?  I certainly was not aware of it.

I understand implied agreements and try to be fair to those with whom I deal but I always reserve the right to think for myself, not divulge my thoughts, and use anything I learn to my advantage.  If a thing is not obviously implied (e.g. is pool hopping ok) then an explicit agreement should be made.  I will not be bound by agreements which exist only in the minds of others and certainly not those which encourage bad mathematics, hidden information, and inefficiency.

You don't have to worry about my taking advantage of non-hopping proportional miners.  I mine with simplecoin.us which uses 'pay per last n shares' and urge others who dislike the mess which stems from the fundamentally flawed 'proportional reward system' to give it a try.