Tab icon size is hard-coded to 27x27pt with no way to override it

[petetan]

Summary

Tab icon size is hard-coded to 27×27pt with no way to override it, which makes it impossible to give a single tab item a larger icon.

Where

Two independent call sites, both fixed:

• ios/TabViewProvider.swift:60 — private var iconSize = CGSize(width: 27, height: 27), applied to remotely-loaded icons via image.resizeImageTo(size: iconSize).
• ios/TabViewImpl.swift:350 — let iconSize = CGSize(width: 27, height: 27) inside makeTabBarItemImage, used on the experimental_bakedTintColors path.

Because remote images are resized to iconSize, supplying a larger source image has no effect.

Use case

We show the signed-in user's avatar as the Profile tab's icon (a snapshot of our own circular avatar component, handed over as a file:// PNG). Design wants that avatar rendered noticeably larger than the neighbouring glyph icons, which is a common pattern for a "you" tab — the avatar is a photo of a person rather than a symbol, so it reads better at a larger size, especially with the label hidden via tabBarLabel: ''.

At 27pt it is legible but visibly smaller than intended, and there is currently no prop, per-screen option, or imageInsets-style escape hatch to change it.

Proposal

Expose the icon size, ideally per screen so one item can differ from the rest:

<Tab.Screen
  name="Profile"
  options={{
    tabBarIcon: () => ({ uri: avatarFileUri }),
    tabBarIconSize: 34, // new
  }}
/>

A navigator-level default (iconSize on Tab.Navigator) with a per-screen override would also work for us. Happy to open a PR if you'd like it in this shape — wanted to check the preferred API first, and whether per-screen sizing raises layout concerns on Android's BottomNavigationView that aren't obvious from the iOS side.

Environment

• react-native-bottom-tabs 1.4.0 / @bottom-tabs/react-navigation 1.4.0
• React Native 0.85.3, Expo SDK 56, New Architecture, React 19.2.3
• iOS 26.5 simulator (iPhone 17 Pro), Xcode 26.6