I would suggest that the Tribunal would consider PCNs issued every hour in respect of a single act of parking to be unenforceable by virtue of being unfair. So, when does unfair and unenforceable become fair and enforceable?
The council's view, to take this example, is that if a PCN is served at 23.30 on 6 July then another could be served at 00.25 on 7 July simply because, according to the council's reasoning and their words, 'As the charges occurred on different dates'.
You could develop this into a draft of your own.m