The limit is not on cinnamon but coumarin. Which means that if you want to put a lot of cinnamon in stuff you have to use the good stuff (Ceylon), not the cheap knockoff (Cassia), where a single teaspoon of powder can exceed the maximum recommended daily dose of coumarin (for flyweights or just generally small people). If you're in the supermarket and it doesn't say which type of cinnamon it is, it's bound to be Cassia. When buying straight bark (not powder): Cassia will be thick, rolled pieces, while Ceylon is thin pieces rolled up into each other.

In practice it was mostly a seasonal issue, e.g. Zimtsterne contain ludicrous amounts of cinnamon and you try telling a kid it can only have one.

And while I'm at it, the cucumber saga: Like with many such things it was the industry who asked for a EU regulation as previously there were differing national standards and they couldn't readily agree on a uniform one. Long story short if growers grow cucumbers straight (not hard) and to a certain size (also not hard), then a certain amount will fit into a standard box, which will have an approximately uniform weight, and a certain amount of those boxes fit onto a standard euro pallet of which a certain amount fit onto a standard lorry bed. Thus, "I'd like to buy a lorry load of cucumbers" is something that makes sense, supermarkets know how many cucumbers they're going to get and they can sell them by piece, not by weight, and everything works out.