The two remaining Zodiac cyphers are very short: 13 characters and 32 characters respectively. As the messages don't share a cypher with the other messages they could theoretically be anything.

The YouTube channel https://www.youtube.com/@doranchak/videos by David Oranchak, one of the people who solved the Z340 cypher, has some more details on this as well as how the Z340 cypher was cracked.