So far I haven't seen any jukugo with more than 4 kanji. Is this a limit? Or some of them are made of more than 4 kanji?
Also, I've seen jukugo made of other jukugo. Like 高速道路 is composed with two other jukugo: 高速 and 道路. What if a jukugo would need to be composed with other jukugo, but those smaller jukugo would sum up to more than 4 characters? Is this something that happened when the language was formed? What happens then?