iOS 16 Photos: Lift Subject & Replace w White Background?

I understand that the ‘lift subject’ feature in iOS 16 allows you to remove a subject from the background of a photo. Very cool except that it leaves you with an irregularly shaped photo without a background. No worries if you’re pasting into a text or email thread but not ideal if you’re using the photo somewhere that doesn’t have a white or other solid color background (think eBay etc).

Wondering if there’s a way (in iOS or elsewhere) to isolate the subject in order to replace the background with a solid white or other color?