iTunes version 12.6.0.100 uses invalid mp3 id3v2 frame for "Grouping" value. How to revert behavior?

This question is regarding iTunes 12.6.0.100 on Windows when managing mp3 content metadata (ID3v2 tag data).

The ID3v2 tag used by iTunes for the "Grouping" value in the GetInfo control panel for managing mp3 content has always been the standard, correct frame, "TT1" for ID3v2.2 or "TIT1" for ID3v2.3 or 2.4. The new frames used to contain the "Grouping" value are now the non-standard / non-legacy / non-specified frames, "GP1" for ID3v2.2 or "GRP1" for ID3v2.3 or 2.4.

This is breaking a lot of software used to access media libraries managed by iTunes.

How can this behavior be reverted?