When I tried Jitsi with my family friends, some of them struggled to use it since they don't know English. So I think changing the language can be easier for nonspeakers of English.

For example, language select box can be placed next to "Go" button (when creating meeting) and next to info button in the meeting. Also using "Accept-Language" HTTP header for choosing the language can be a good default. Another option is to add a language query parameter to the URL so that host can easily share meeting with a particular language.

Also if it would be great if some improvements can be made for low bandwitdh since there are people with slow connections and limited data plans. (On the other hand, there is already an option to lower video quality).

Other than that, kudos to Jitsi team for their great efforts and this great project.