Yes FD is a contest but that does not mean that consideration, fairness, and the goldren rule should be abondonded.
The point, which is obvious to everyone, is that the single QSO per FM channel rule was introduced in order to try and reduce the chaos that occured with hundreds of stations trying to make multiple QSO's with the result that practucally no one made a QSO.
99 percent of the time ONE QSO means ONE QSO. You have got your lolly pop. You dont need, nore can use, five more and even if you are offered one you should decline and let someone else have it.
There may be the very odd time when someone calls several CQ's and does not get a reply in which case a second QSO my be justified.
It just takes courtesty and some commen sense.
If you really want to get into the contest mode get on the linear transponder birds where each QSO counts and where experience and operating skill really shows up.
A lot of rule deffinition should not be required. EVERYONE knows the intent and should operate accordingly.
It may be of interest to note that while in Canada we have band plans they are not Govt. regulations. They are completly voluntary and I have not heard of a single instance where a Canadian amateur has intentionaly not followed them.