Yes, this is exactly my intention. So the format of the tracknumbers is also compatible with the Auto-numbering wizard. It's still saved in these two seperate fields, but this is done transparent to the user.
Yes, this is because Mp3tag prefers another tag format which is written to the files over Apple's hack.
On the Tracks & Total Tracks\Discs & Total Discs topic, my point of view is that they should behave in the same way since (to me) they are the same construct. I don't think we should have to different formats for the same concept.
This is because ID3v2 doesn't have an extra TOTALTRACKS or TOTALDISCS field specified. If you create these fields, Mp3tag stores them as user defined TXXX frames. Both values are stored in TRACK and DISCNUMBER (separated by a slash).
This is because the current version hides the TOTALTRACKS and TOTALDISCS fields from the user to display the same as for MP3.
This is because you've created extra TXXX frames for TOTALTRACKS and TOTALDISCS. If you want these values automatically mapped to x/xx format in TRACK or DISCNUMBER, the fields won't be available to users who use these fields in other programs (like foobar2000).
I still have no idea how to solve this. These tests are not very new to me.
Yes, I've changed MP4 track/discnumber field to accept input in #/## format, but I'm displaying them as seperate track/totaltracks and discnumber/totaldiscs fields (because they're stored as seperate fields in the tag).
MP3 track/discnumber handling has not been changed.