Adding custom shortcuts to Modern UI

It is possible to add custom parameters to a program that is already pinned to the Start page.

Open the Start page, then right-click the program that you want to add parameters to. Choose Open file location at the bottom of the screen. This will open an Explorer window to the location of the shortcut file.

Right-click the shortcut file and choose Properties. In the Target: field, add command line parameters after the program file name.

Any shortcut you create (including switches) you can simply right click and "Pin to start" which will create a copy of it in the appropriate places.

Yes, the Modern UI start screen takes the shortcuts from the Start Menu so it should be sufficient to place the shortcuts in the start menu folder. You can also edit an existing program by opening its location from the Modern UI start screen. It might be so that it might not work to place multiple shortcuts to the same program there or those with parameters as it might just take the program itself, if that's the case you might get around the issue with batch files or by creating exectuables with something simple like AutoIt3 which automatically execute the program with parameters.