Deriving mtxcfg default filename is rather strange

Let's say we save the current settings as

• D:/This/is/a/test/file.mtxcfg

In mkvtoolnix-gui.ini, this entry is added:

• lastConfigDir=D:/This/is/a/test

Now, let's create new multiplex settings and add this source file:

• D:/Another/video.mkv

Clicking the Save Settings As button suggests the following filepath:

• D:/This/is/a/test/test.mtxcfg

which doesn't really make any sense. The path should be

• either D:/Another/video.mtxcfg
• or D:/This/is/a/test/video.mtxcfg

(I'm using MKVToolNix GUI v52.0.0, on Windows 10)