If you edit one track yes.
But if you batch edit many files this doesn't work
I see that you're right about that.
A little trick to circumvent that:
Select all files, in Tag Editor select a tag field that you are not using and/or presently has no content, type anything there, and save.
Then all files will be converted to 2.4.
After that you can easily delete what you had entered in the unused field.