Dan3468298 MacOS and iOS have different controls (
https://www.raywenderlich.com/759-macos-controls-tutorial-part-1-2). For example, MacOS uses NSButton, NSTextField, etc while iOS uses UIButton, UITextField, etc each tuned for their mode of interaction (mouse/keyboard vs touch). While tools like Catalyst aid the porting of iOS apps to MacOS, going the other way would be a challenge. Historically, one uses an x86-64 Mac to build executables to ARM-based iOS devices, using Xcode or Lazarus (
https://wiki.lazarus.freepascal.org/iPhone/iPod_development). I think it would be hard to compile Arm-Mac tools on an iPAD as it does not have the sdk. I think it would be hard to port the Lazarus IDE to iOS as the user interface would not translate over.
I do think that one can create an FPC compiler for x86-64 that emits Aarch64 code. This would allow an x86-64 user to generate both x86-64 and Aarch64 executables that you could lips into a single executable to target either platform. Likewise, a Aarch64 user can create a compiler that emits x86-64 and create universal binaries.
For my tools, the current FPC and Lazarus support Aarch64 just fine. The only issues I had were hand-built assembly that leveraged x86-64 specific routines (e.g. SSE2). Beyond those unusual (and expected) challenges, support of this new architecture seems pretty seamless.