lemmy.ml is on 0.18 so jerboa 0.34 doesn’t work with it, only 0.35. Shouldn’t crash but well…
Honestly I’d suggest using the browser, the web interface works perfectly well on mobile. If you use Firefox or any other browser that can install UserScripts, you can add some useful ones like https://greasyfork.org/en/scripts/469273-lemmy-rewrite-links-to-home-instance and https://greasyfork.org/en/scripts/469196-gm-lemmy-newtab
You could use Firefox on mobile and use ublock origin to auto-block images & third-party content by default, then it doesn’t use almost any bandwidth. I’d imagine jerboa uses similar amounts since it also displays images without any data saver settings as I can see.