For TC 11.51rc5 the help says:
Help wrote:PhotoAppMode=0 Override how the Microsoft Photos app is called to load multiple images:
0: automatic based on photo app version number
1: old method (LaunchFileWithOptionsAsync)
2: ms-photos:viewer?fileName=name with URL-encoded name,
3: ms-photos:viewer?fileName=name without encoding the name
-1: open photos app with only one file
But the history says:
history.txt wrote:11.02.25 Added: wincmd.ini [Configuration] PhotoAppOverride=0 : override how Microsoft Photos app is called to load multiple images: 1=old method, 2=ms-photos:viewer with URL-encoded name, 3=ms-photos:viewer without encoding the name (32/64)
The correct parameter name seems to be: PhotoApp
Mode as stated in the Help. and parameter -1 is not documented in the history. German Help also usee PhotoAppMode.