Command line arguments: How to launch 7zFM.exe like the context menu does, so that prepared 7z GUI appears?

Solution 1:

If everything was easy like this. - The Task Manager's "Details" tab gives it away. The syntax is:

"C:\Program Files\7-Zip\7zG.exe" a -ad -saa -- "D:\eula.2052.txt

I left out the -i#7zMap7448:36:7zEvent28001 part because apparently that refers to the immediate user action that could somehow be evaluated by the program, but the command line start doesn't have such action, so the error in the screenshot appears.

Also in the screenshot: The result of the proper call, the one without that extra argument.

Due to dumb luck, I also immediately figured out how to do all that with giving a desired file name:

"C:\Program Files\7-Zip\7zG.exe" a -ad -saa "BLABLABLA" -- "D:\eula.2052.txt"

This opens the shown window with the desired file name plus ".7z", and confirming the dialog will indeed compress the desired file into an archive of the file name, which is different from the file.