How to associate Photo Viewer using ftype and assoc

Hello.
I want to associate png, bmp, jpg/jpeg with Windows Photo Viewer in Windows 10 (8.1) through console and without using GUI (Settings — Apps — Default apps — setting up Photo Viewer as a default app).
Here is my code, but unfortunately it doesn't associate at all, but works with out any errors. Restarting Explorer or PC doesn't help.

Code:

IF (!(Test-Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\command))
{
    New-Item -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\command -Force
}
IF (!(Test-Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\DropTarget))
{
    New-Item -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\DropTarget -Force
}
IF (!(Test-Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\print\command))
{
    New-Item -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\print\command -Force
}
IF (!(Test-Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\print\DropTarget))
{
    New-Item -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\print\DropTarget -Force
}
New-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open -Name MuiVerb -Type String -Value "@photoviewer.dll,-3043" -Force
New-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\command -Name "(Default)" -Type ExpandString -Value "%SystemRoot%\System32\rundll32.exe `"%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll`", ImageView_Fullscreen %1" -Force
New-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\DropTarget -Name Clsid -Type String -Value "{FFE2A43C-56B9-4bf5-9A79-CC6D4285608A}" -Force
New-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\print\command -Name "(Default)" -Type ExpandString -Value "%SystemRoot%\System32\rundll32.exe `"%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll`", ImageView_Fullscreen %1" -Force
New-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\Applications\photoviewer.dll\shell\open\DropTarget -Name Clsid -Type String -Value "{60fd46de-f830-4894-a628-6fa81bc0190d}" -Force

cmd.exe /c "assoc .bmp=Paint.Picture"
cmd.exe /c "assoc .jpg=jpegfile"
cmd.exe /c "assoc .jpeg=jpegfile"
cmd.exe /c "assoc .png=pngfile"
cmd.exe /c "assoc .tif=TIFImage.Document"
cmd.exe /c "assoc .tiff=TIFImage.Document"

cmd.exe /c 'ftype Paint.Picture=%windir%\System32\rundll32.exe "%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen %1'
cmd.exe /c 'ftype jpegfile=%windir%\System32\rundll32.exe "%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen %1'
cmd.exe /c 'ftype pngfile=%windir%\System32\rundll32.exe "%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen %1'
cmd.exe /c 'ftype TIFImage.Document=%windir%\System32\rundll32.exe "%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen %1'

Source: https://www.reddit.com/r/sysadmin/comments/72vv31/set_windows_photo_viewer_as_default_app_on/
Source 2: Forcing Windows to use Windows Photo Viewer | NHL Data Blog
How to really(!) associate an file extension to new program? - DosTips.com

Why not
a. associate it
b. export the relevant keys
c. build a reg file that you can merge
registry - Add reg file via Command Line on Windows CE device - Stack Overflow

Just a thought..

So your question becomes
If I merged the registry file, would the effect be immediate?
Quite often registry changes require that explorer be restarted to be applied. I've not experienced what happens if you change associations by editing the registry though.

I assume you are experiencing a change in association, and want this always to be photoviewer.
If so, the question then is - what is changing your association?

Otherwise perhaps you could state the perceived problem you're trying to solve.