Since predictive back is now enabled by default, it would be better to have it polished and match the native behaviour, currently it uses a fixed border radius when the effect is active, which looks bad, Android provided APIs that get the devices corner radius which can be used to achieve a more seamless effect and match the native side.

Current implementation:

in my custom implementation, all I did was use a ClipRRect on a whole page and set the corner radius to the device's using this package corner_radius_plugin, it uses official Android APIs to get the devices corner radius.

the result is a more native behavior: