[sciurius]

I have a chordpro file containing chords in C. It is transposed via transpose function to A, 3 semitones down.
When I open it in the new Text Editor, it shows chords in C as written in the file - OK so far.
When I tap "Transpose" in Text Editor, the transpose window shows "F#" (3 semitones down from A), I would expect it to be intialized with "A" like in the original, three semitones down from the displayed "C" chords.

Actually, I would expect to see "C", since the text file being edited is, still, in the key of "C".
The text editor edits the ChordPro text document, so it should use the key the document is in.
That it is displayed in some song window in the key of "A" is not relevant. The same file could easily be related to another song and displayed in yet another key.
Upon save, I'd expect MSPro to perform the equivalent to a "Swap file".