I don't know anything about Expo.. but from a quick Google search, it seems like it pares down what you can actually do.. including the fact that you may not have access to Native code, and only JS??
I feel like this would potentially compromise your ability to do proper native app tracking... that said, you can probably run your app tracking by using JS (similar to how Adobe used to be tracked with JS files and setting values, then triggering the s.t() and s.tl() beacons...
This however will kill some of the features of Mobile App tracking, such as Lifecycle Metrics and Mobile App Versions... but you could probably code a prop or eVar with a "version id"... but Lifecycle would still be out....
However, tracking this like a website would be better than nothing...
However, it might be worth asking Adobe if they have any experience with Expo (since my answers may not be the most informed)