Don't see any deprecation warning, due to "deprecated: 100000.0"? What's the rationale for marking it this way?!

One temporary, mediocre solution I found was to open the Xcode project file (e.g. MyProject.xcodeproj/project.pbxproj) in a text editor and replace IPHONEOS_DEPLOYMENT_TARGET = 14.0; by IPHONEOS_DEPLOYMENT_TARGET = 100000.0; You'll get a lot of errors when you open the project in Xcode again (tested with Xcode 13.0) but also the deprecation warnings for the open SwiftUI files in the Xcode editor.