Our games use Godot Share for saving and sharing images from within our games on iOS and Android. When iOS 17 came out with the sticker creation feature we played around with making stickers from the photos saved with the Godot-Share plugin. For some reason the segmentation algorithm iOS uses seems to work much better with jpeg than it does png. The Godot-Share plugin defaults to png so I created a quick fork on github that converts to jpeg for iOS.
It’s only a few lines of code, and a more complete solution would make it configurable but I just went with what works (no need to update Android).
I hope someone else finds it useful.