Does the MSIX Packaging tool support multiple architectures, and how does that work?

Here is some context of my current situation:
I have a very simple install, three executables and three DLL's and one desktop Icon;

My Installer I am using is InnoSetup, which detects the architecture and, then installs the relevant executables and DLL's depending on the architecture.. The output of this build is a single exe, installer.

; "ArchitecturesInstallIn64BitMode=x64 arm64" requests that the install
; be done in "64-bit mode" on x64 & ARM64, meaning it should use the
; native 64-bit Program Files directory and the 64-bit view of the
; registry. On all other architectures it will install in "32-bit mode".
ArchitecturesInstallIn64BitMode=x64 arm64

[Tasks]
Name: "desktopicon"; Description: "{cm:CreateDesktopIcon}"; \
    GroupDescription: "{cm:AdditionalIcons}"; Flags: unchecked

[Files]
; Install MyApp-x64.exe if running on x64, MyApp-ARM64.exe if
; running on ARM64, MyApp.exe otherwise.
; Place all x64 files here
Source: "MyApp-x64.exe"; DestDir: "{app}"; DestName: "{#MyAppExeName}"; Check: InstallX64
; Place all ARM64 files here, first one should be marked 'solidbreak'
Source: "MyApp-arm64.exe"; DestDir: "{app}"; DestName: "{#MyAppExeName}"; Check: InstallARM64; Flags: solidbreak
; Place all x86 files here, first one should be marked 'solidbreak'
Source: "MyApp-x86.exe"; DestDir: "{app}"; DestName: "{#MyAppExeName}"; Check: InstallOtherArch; Flags: solidbreak
; Place all common files here, first one should be marked 'solidbreak'
Source: "data.dat"; DestDir: "{app}"; Flags: solidbreak
Source: "myapp-amd64-lib.dll"; DestDir: "{app}"; Flags: solidbreak
Source: "myapp-arm64-lib.dll"; DestDir: "{app}"; Flags: solidbreak
Source: "myapp-x86-lib.dll"; DestDir: "{app}"; Flags: solidbreak

[Icons]
Name: "{commondesktop}\{#MyAppName}"; Filename: "{app}\{#MyAppExeName}";  WorkingDir: "{app}"; \
    Tasks: desktopicon

[Run]
Filename: "{app}\{#MyAppExeName}"; Description: "{cm:LaunchProgram,{#StringChange(MyAppName, '&', '&&')}}"; Flags: nowait postinstall skipifsilent

[Code]
function InstallX64: Boolean;
begin
  Result := Is64BitInstallMode and (ProcessorArchitecture = paX64);
end;

function InstallARM64: Boolean;
begin
  Result := Is64BitInstallMode and (ProcessorArchitecture = paARM64);
end;

function InstallOtherArch: Boolean;
begin
  Result := not InstallX64 and not InstallARM64;
end;

1: I am not sure if  InnoSetup`s produced single installer (setup/install.exe) is truely cross architecture compatible; I would think not. (however my install script is based InnoSetup's provided sample).

2: When I run the MSIX packaging tool, and capture the install.exe, using Parallels/MacOS, where the GuestOS is Windows 11 arm64, the resulting MSIX, appears to install the x86 executable. (When I inspect the "virtual file system", I did not run the msix installer locally).  

I want to submit the application to the store/partner centre, and it appears there is only a "single" package to be uploaded and not separate packages per architecture.

Ultimately I am intending to support x86,  x64 and arm64.

Thanks for assisting.