I’m not sure if I’ve just not figured it out yet, but there are very few options for connector label texts. It would be nice to be able to change font size and add support for multiline text. It might also be useful to change text color.
In general FigJam seems very limited in contrast to Figma Design files (probably on purpose since it makes the workflow lightning fast), but I would love to see some more basic functionality (as mentioned above), which FigJam is currently lacking.