[chrismsimpson]

Apple control iOS, iPadOS and visionOS. Not only that, but they made their UI frameworks screen resolution/size independent some years ago. I am sure Apple will be able provide a premium ‘native’ experience for existing deployed iPad apps with minimal to no additional effort on their part. Does Catalyst ring a bell?

[piva00]

The apps need to be enabled to run on other xOS devices, an iPad can run iOS apps but the developer need to enable the flag.

In this instance it would be the same, visionOS can run iPadOS but the devs won't enable the flag.

If Apple strong arm them to run without a flag it can get pretty messy for Apple since they would be taken over control of what the app developers allow or not with their own apps.

[Mindwipe]

Also developers would just put their own application logic to detect portal size etc and disable it that way.