As someone who appreciates apps that tailor to each specific platform and respect that platform's unique features and guidelines, this scares me.

React Native doesn't make it so you share UI code between platforms (https://facebook.github.io/react-native/docs/platform-specif...). What you get to share is all the business logic between tailored UIs.

You can share UI code between platforms if you want, though!

At least Android + iOS. Some components are platform- specific but at least on a small simple app I've been successful sharing my UI code.

I haven't yet done any React Native, but it seems to me that hypothetically, you can share or not share as you go down the component tree. I can imagine dedicated layouts per platform, then shared widget clusters, then dedicated low-level widget implementations.

Yup, there is an entry point for both the Android and iOS app. You can point to the same root component or a separate one if you want separate layouts orwhat have you

Is it possible for tooling to maintain a lot of these quirks and then implement additionally on top of areas it falls short?