full
town buy-in, you can reveal quite a lot about who is and isn't the cop before you even start looking at claimed results (eg, cops will be acutely aware of the hypocop strategy, which means if say the plan is to reveal "cop results" on your first post each day, not doing so is a less-invested tell, i.e. a non-cop tell). Obviously, the more people talk about the cop, the easier it is to find a cop. There are other tells as well - for example, what if you just ask people for a target and alignment, but the cop gets rolename details? Or was roleblocked? Or there's a watcher - should he factor in his findings to the hypo-cop plan or not?Secondly, it requires town buy-in. People only have a certain amount of investment in a game, and focusing on one plan takes energy away from others. The question isn't just "is this plan good or not?", but also "is this plan better than other plans which take a similar amount of work?".
Thirdly, it places excessive attention and focus on the cop. Put this much effort into a single plan, and people will try to get value from it - which in turn means overvaluing the cop, which is already a big problem in setup-following.
These plans almost always collapse under the weight of their own ambition - by trying to break only a very tiny aspect of the game, you end up gaining little but spending a great deal of energy. Very rarely a good idea.