KWrite, save, having file types other than "All files" in the dropdown?

If I start Kwrite without opening a file, and then click the save button, the save dialogue has only one type: “All Files”, and also, ‘Automatically select filename extension’ is disabled. So, I have to type ‘.txt’ in the file name every time.

The behaviour I want is that when the editing mode is ‘Normal’, if I click the save button, the save dialogue has ‘*.txt’ in the file type dropdown. Is this currently possible?

It would be better if ‘*.txt’ is chosen by default when the editing mode is ‘Normal’, but ‘.json’ is selected by default, if the editing mode is ‘Json’. Currently, no matter what the editing mode is, the save dialogue shows only ‘All Files’.

KWrite
Version 25.08.1