That sounds interesting. There must be apps that do require full access (like a finder alternative), so I wonder if you can know to trust an app to be isolated just by looking at it.
It has some interesting side effects. For example Zoom links don't work in the Flatpack version of Firefox. Ironically the Zoom app Firefox tries to open is in itself a Flatpack app. Not sure if this is by design or if there is a way to fix it.
