Hi!! Thank you for making a suggestion about this!! I'd like to say a thing or two about it :D.
Too much caps is punishable, but de always verbally warn before doing so (certain situations excluded). Usually, players will stop after we just ask them to, so there usually isn't really an issue. The most situations of "excessive caps" I've seen is just when someone gets excited about something. I feel like it would be bad if people who are just excited instantly get warned.
For something that auto warns, I feel like that could bring more issues than not for things like this. "when is too much caps actually too much?", "what's the situation the caps are used in?", "is it really something worth warning or punishing for?",... Are things a staff member thinks about when seeing caps. An auto warn system won't be able to do that (as efficiently as staff) unless it's an AI. I feel like the same thing can be said about a filter. What would be the threshold of having too much caps to change it? I feel like it changing would just annoy people who want to express their excitement once.
In short, I believe caps are usually fine unless it goes way too far, so some staff discretion is needed. I do thank you for trying to think of ways to improve our server!! I'm hoping you can come up with other good suggestions :D