Using a custom difference viewer

Environment: Delphi 11.3

How can I make Delphi use a custom difference viewer to compare file versions ?

I want to use WinMerge instead of Beyond Compare

I have configured it in the Delphi options, but it is still using Beyond Compare when I do the comparison

This is my options

To do the comparison, I open both files.
On the first file - I click on the tab and select “Select left File for Compare”
On the second file - I click on the tab and select “Compare to ”

When I do this, it always uses Beyond Compare instead of WinMerge

How can I make it use WinMerge ?

I worked out one way to do this by using the HISTORY tab.
However that only compared differences that are in the Delph file history.

I want to compare one file to any other file even if it is in a different folder - I open one file, and then open a secod file - and I want to compare those two files

I came across bug RSP-38891 that prevents you from restoring the viewer back to the default after you setup an external viewer

My original question remains unanswered - but I thought you should be aware of the bug in case you try to play around with this setting

The clue is in the menu items icon (bc logo) - I don’t have the beyond compare IDE plugin installed and don’t see those menu items - that suggests they are probably beyond compare specific.