Mp3tag has for some time been able to display the presence of unsupported tag frames and also to remove them.
In my opinion, this removal could be improved.
Initially, this was done by cutting and pasting tags, whereby I always restricted myself to a limited number of files out of caution.
Later, the ‘Remove unsupported fields’ function was added. (Right mouse button on selection -> Remove unsupported fields).
In my workflow, which also includes external software, unsupported fields regularly occur, which I would like to remove in a final processing step within one of my existing action groups.
Unfortunately, this is not possible in an action of the type ‘Remove fields except’ or in an action at all, so that the additional step must always be taken via the menu function.
I therefore suggest including this function in an action of the type ‘Remove fields except’. For security reasons, the radio button should be activated by default. However, a separate action for this purpose only would also be conceivable.
The existing function under Utils should continue to exist.
However, I see a disadvantage in the existing configuration. To be able to select this function, there must not be any ‘non-music files’ in the file selection. I'm probably not the only one who also has files such as JPG, PNG, PDF, TXT etc. displayed in the list view. So you have to be very careful not to include such files in the selection when marking them. A quick selection via CTRL-a is therefore not possible. In my opinion, it would be desirable if this logic circuit could be omitted when hiding the menu. With the solution using Cut&Paste (CTRL-x - > CTRL-v) there are no problems if a non-music file is also in the selection. I therefore assume that there are no insurmountable technical problems with this change.
I'll put my suggestion up for discussion. Perhaps someone has an improvement to the design or realisation or an opinion for or against it.

