react-native-media-query VS capacitor-codepush

Forking RNW is an option. But if you are worried about maintaining a fork of RNW with potential style inconsistencies, then react-native-media-query is already that fork. It attempts to do media queries inside RNW's StyleSheet.

Not yet responsive, but planned responsive under SSR with react-native-media-queries, which makes pure CSS media queries run on native (with device orientation), since Magnus UI generates pure CSS media queries when run on web. They consider it more performant than using Fresnel. But the jury is out..

Of course it’s not all butterflies and rainbows, you’ve already touched on the css limitations such as the positioning fixed & the likely difficulties you’ll face if implementing a drag to upload feature, but if you can live without these features, and for some such a the lack of media queries, you can easily work around by calculating width with Dimensions or this library https://github.com/kasinskas/react-native-media-query#readme (not used this myself so not sure how well it works)

NB: Using Capacitor in practise means bundling your website inside the app, NOT loading it on demand (via a url). That is the recommended option from Capacitor’s creator Max Lynch, since if not: "Apple will likely reject your app since it is not “self-contained.". To make it self-contained, you can do a NextJS static export, for example. Sadly, for distribution, this means going through the App Store process, and asking clients to update their app for every code change (many will thus be out of date). Unless you use a service such as CodePush for Capacitor. Never mind the weirdness of using a code distribution tool for native apps, just to serve users with fresh HTML, CSS and JS...