Not possible to change filename w/ extension via file view

[ptrk.mj]

I'm not searching for a workaround. I know I can do this with an action. I've reported this as I considered it a bug/oversight.

Changing the content of %_filename_ext% from within a list view cell with consequence to the real filename should not be accepted anyway by Mp3tag.

Why?

In my opinion setting 'Field' to %_filename_ext% should result in modification of filename with extension even though it may cause Mp3tag not see the file (if you change extension to one denoting unsupported file format).

The default setting is %_filename% so it wouldn't cause any trouble for those not fiddling with their column settings.

There is only one action in Mp3tag which can do this:

That's right. Another inconsistency. If "Replace with regular expression" applies regex to the whole filename than why "Format value" should act different?

I think the best solution would be to provide two pseudo tag-fields _FILENAME and _FILENAME_EXT in the future.