We have the same issue. We removed the platform in xcode and left the ipad for Mac platform. That new version has been available for some time in production. What we have noticed though is that we can still see the Catalyst version on our Macs and that the ipad tab to download apps does not show our app. We believe this could be because we previously have downloaded the Catalyst app. We hope at least new users do not see our app in the Mac section but instead have the option of downloading it from the ipad tab on their Macs. We developed the catalyst app before even knowing the ipad version would become available on Macs with the right CPU. Apple please advice us on how we do this transition. Or at least give people a choice of selecting the ipad version on their Macs so previous users are not stuck with the older unsupported versions of the catalyst app.

We have a similar issue but coming from wanting to remove the Mac Catalyst platform while keeping the iphone, ipad, and ipad for Mac platforms. We have removed the catalyst platform in xcode and have a production build with this. However people who downloaded the Catalyst build previously can still download and see the catalyst app on their Mac. So removing the platform in xcode did not help us. It may have helped new users to the app. So Apple please let us know how we can fully remove a platform and not have users stuck using old versions of our apps that are not longer supported.

I got around this issue by opening the storyboard as source code (control click storyboard -> Open As) and updating the value directly. e.g setting the font as I found the line I was working on by looking at my source control but I also could have found it by changing the font to one I am not using anywhere else and searching for it in the code to replace with the custom font. If you have no previous reference on what to set the font as look for code that prints out all fonts by using UIFont familyNames and then fontNamesForFamilyName. There are a few code examples about. But since you are using font awesome it will probably look like the example above. Could be Font Awesome 6 Free and FontAwesome6Free-Solid if you are using version 6.