Heh, this is probably way too late to help you out, but FWIW, I have found that one very quick and dirty way to get at the messages is to do a “git log --reverse” when in the conversations folder on the desktop version of Jami.
It’s less than ideal, and a plugin would be much better, but it does give you the conversation text (along with a lot of extra stuff I don’t necessarily want) in chronological order.