iOS code that sets up channels manually (not plugins).
The old architecture could lead to inadvertent retain cycles. For example:
FlutterEngine *-- FlutterPlugin *-- FlutterMethodChannel *-- FlutterEngine
This is of particular interest to the add-to-app flow.
Plugins usually get the binary messenger from the FlutterPluginRegistrar (ex. [registrar messenger]), so they shouldn't be affected.
This proposal should be an easy migration that shouldn't affect many people. Let me know if this would be a problem for you.