if there is no strict guidelines or rules for bounty managers.
Exactly and already OP mentioned about that.
And if there isn't such a board, should a board with very strict rules for campaign managers and participants be created?
Still you could run spam free campaign if thread is self moderate.
It will not work actually since OP has to spend a huge time to delete the bumping which about he is talking about.
Really should not give freedom to bounty managers. If no rules for them than spam will never end.
In fact, bounty managers are at least 60% responsible for the worst situation of a bounty thread.
@LoyceV
There is no other possible way without creating a new board, imo too as other people already mentioned.