I replied above as well. My team has also not been satisfied with the performance of the GPay app on all devices. We've been working with the GPay team since release and made many improvements in both Flutter and the GPay app. I expect there will be an updated GPay app soon, with still more performance improvements in the pipeline.
Maybe publish a Flutter showcase app on both appstores? With Apple's store you'll probably have to jump through some hoops to provide some useful functionality, but it should be doable.
I replied above as well. My team has also not been satisfied with the performance of the GPay app on all devices. We've been working with the GPay team since release and made many improvements in both Flutter and the GPay app. I expect there will be an updated GPay app soon, with still more performance improvements in the pipeline.