OP i once made a comment about merit allocation being carried over to the upper month when there is no much quality posts in the local board but am happy that you came across where Theymos stated that instead of allowing the source to expire, it will be better to empty them on the little quality posts you come across. However, there is no limit to how many merit you can give a post inasmuch as it is a quality post. The merit system is not moderated hence you can decide to award a post any number of merit you wish to, there is no rule or law against that.
It is sad to see that your merit allocation monthly is being carried over when the local board is lacking behind in merit distribution/circulation and complaints have already been made to this regards.
I will advice you not to ask this kind of questions next time so far you are giving the merit to quality posts.
Am even surprised about the need for this thread but since it is for the interest of the local board i think there is no problem with it.