Hans♫

It is the same when running outside the IDE.

I use ScreenService.GetScreenScale to get the Screen scaling. It was partly broken in 10.2.3, but in 10.3 it seems to be completely broken. 

In 10.3: No matter what scaling is set in Windows: 150%, 175% or 200%, the return value of ScreenService.GetScreenScale is 1.0. 

In 10.2.3 it did return the value 1.5 with 150% scaling, but with 175% and 200% scaling it also returned 1.5

I post it here before I post it as a bug in QP, in case I missed something...?

This is the function where I use it (and yes it does actually call GetScreenScale):

function tScreenScale.GetScreenScale: Single;
var ScreenService: IFMXScreenService;
begin
  Result := 1;
  if TPlatformServices.Current.SupportsPlatformService (IFMXScreenService, IInterface(ScreenService)) then
    Result := ScreenService.GetScreenScale;
end;

Problem solved. It was a license problem. I contacted Embarcadero support and they gave me different serial number for my subscription, which solved. It required me to reinstall 10.3 though.

iOS does not exist as a platform I can choose anywhere in 10.3. Even if it did exist, AFAIK I would still be required to choose an SDK before I could add iOS as a target platform in a project. But I cannot add any iOS SDK at all, as described in my question.

Edit: and when I want to add a SDK, I have to choose the platform before I can choose what Connection Profile I want, which leads me to conclude that it has nothing to do with XCode because it doesn't even connect with XCode to check, but maybe the macOS build caused the iOS platform to be removed?

Edit2: I tried to build and run an empty iOS app with XCode, then building and running a macOS app with Delphi, but still no change.

Yes, I have a connection profile and it connects fine with paserver. I can build, deploy and run a macOS application. 

My Delphi 10.3 Rio installation has no iOS target:

SDK manager > Add > Select Platform: There is only Windows and macOS on the list. iOS is not there.

Tools > Manage Platforms: shows that iOS target is installed.

paserver runs and connects fine on the mac, as I can build and run macOS applications from 10.3 Rio.

I have installed MMX, CnPack and Project Magician.

What can I do to make the iOS target show up?

Great, thank you. I missed that change of the project.

I have been using the Dproj Normalizer with great pleasure. Its doing a great job to minimize the changes of the .dproj file when committing to version control.

However, the latest version does not include 10.3 Rio as an installation target. Is there an update on the way?- or did Delphi include its own solution to make a structured organization of the .dproj file in 10.3 Rio?