Technically, this may impact non-iOS UIs too, and that's the only risk that I can think of.

I had that concern as well, hence I added @supports (-webkit-touch-callout: none) { which is a media query to restrict the changes to iOS. Though I have NOT tested it on other platforms (aside from Mac Catalyst).

Glad to see the progress here!

Final question: is there any straightforward way for a developer to prevent the overscroll/bounce effect when scrolling the root scroll container? Having overscroll at the page root makes it feel like not-a-real-app, since fixed/sticky menus bounce around in a way they wouldn't if it was a native app.

This is a longstanding problem for PWAs on iOS that is solvable on Electron. It would be great if this is solvable easily on MAUI too.

Final question: is there any straightforward way for a developer to prevent the overscroll/bounce effect when scrolling the root scroll container? Having overscroll at the page root makes it feel like not-a-real-app, since fixed/sticky menus bounce around in a way they wouldn't if it was a native app.

This is a longstanding problem for PWAs on iOS that is solvable on Electron. It would be great if this is solvable easily on MAUI too.

Looks like we need to add a custom handler to disable the bounce on the WKWebView?

https://github.com/ionic-team/cordova-plugin-ionic-webview/blob/ab7dfc06a7f8780f75800dae4f4217d1956aa7b6/src/ios/CDVWKWebViewEngine.m#L474

Maui doesn't yet facilitate control of the iOS status bar. Next best alternative is to have an iOS specific placeholder for the status bar, which is what this PR now accomplishes (alongside better support for notch'd devices).

Having overscroll at the page root makes it feel like not-a-real-app, since fixed/sticky menus bounce around in a way they wouldn't if it was a native app.

I totally agree and I believe we should spend some time to fix this up. I've created #6689 to track this. As far as I know, there's no "quick & easy" way to do this, and Apple isn't a fan of users disabling this functionality (I could be mistaken). Take this article for instance which shows how it can be disabled in Chrome/FireFox, but not Safari. The workarounds mentioned have also since been disabled.