Forking this out from #3573. Probably I should have made separate issues in the first place.

We use react-navigation for navigation in the app. We're on version 2.18.3. There's a new major version out, v3. (We were on v1 until not long ago; getting to v2 was #3573.)

The v3 releases contain various bugfixes, as well as compatibility with newer other software. Issues blocked on this upgrade include #3569, and possibly #2716 and #3566.

There's partial work toward this issue in #3502.