> The one way to address this would be: a person can only operate
> with one call/contribute to one station for the duration of the contest.
Contributing to more one than one score is called "Highly Motivated
Operator" or HMO operation and as far as I know, is allowed in all
contests. It may not make sense in all contests but is not ruled out.
There are some contests with distinct rules about what constitutes a
station and what constitutes an operator and what constitutes a contest
log, that require a certain structure for HMO's. Sweepstakes is an example.
There are also writings discouraging the other way around: use of multiple
calls at same station for the purpose of cheerleading. Here's some writing
on that in relation to IARU HF:
CQ-Contest mailing list