I'm a bit indecisive in this situation. I can see valid arguments from both sides. But as it currently sits, it's hard for anyone that isn't a BAT to actually enforce this. Kiai fountains don't bother me even if they are spammed unless they use a lag inducing fountain. I don't usually bring it up, but I don't think it ever got to the point of being excessive (except Fairy Tale). Excessive fountains is just a ridiculous thought. The person who would violate this rule does not know how to map, so it's not really applicable for the average mapper who would get a map that is ready to be ranked.
Times have changed since the old days where mappers had to follow strict standards for maps. I don't think that the circumstance for kiai is as important to today's standards. From my knowledge the only reason this rule exists was to prevent toggling kiai fountains when kiai fountains were only meant to indicate the start of a kiai time. The guideline appended to the rule that now allows this undermines the internal purpose of the rule. essentially this rule is now purposeless, because no map would benefit from the amount of kiai spam required to violate this rule. The standard of what is excessive has changed from past definitions.
What we need is a redefinition of this rule that matches today's standards. We need to include specific details on what is not allowed. The current guideline is that kiai shouldn't be toggled more than once a minute or in other words you can use a fountain once every 30 seconds. The rule doesn't require the kiai to be used for any specific duration. AiMod will give a warning when more than 1/4th of the map is kiai, but there is no guideline about keeping kiai under this amount. AiMod makes it sound like it's a guideline to not overuse kiai. I'm pretty sure toggling kiai more than once a minute is an error according to AiMod.
If we want this to be a rule that prevents kiai fountains, then state "Kiai fountains must be used to indicate the start or end of a kiai section". That would be enforceable by any modder. Allowing the usage for rare situations is vague and no normal modder has the authority to decide what is considered a rare situation and they will be ignored by anyone who actually believe they are using kiai correctly. this would be even harder to enforce if it were a guideline, because even MATs get ignored when it comes to guidelines.
I think we should clear up the actual definition of this rule. Abusing kiai fountains is not really considered overusing kiai. A song can spam fountains with the same number of kiai sections as someone who is not overusing kiai, because it is not based on the length of the actual kiai. I think that overusing kiai should refer only to using too much kiai in your map. Using fountains incorrectly/ too close to other fountains is considered abusing kiai, not overusing it. BATs will refer to it as kiai abuse. I refer to it as kiai abuse. It should be Do not abuse kiai usage or the idea in the previous paragraph. Overusing kiai should focus on the actual duration of kiai and be demoted to a guideline.