Idk if these been posted but I added a couple mixtapes and songs that are on iTunes and it worked
Add song to iTunes then make a AAC version of them, delete the original ones and it should upload them not match it.
You could also just rename the tracks so that it does not find a match.
Example:
Change
Track 1
Track 2
And so on.
To
TempTrack 1
TempTrack 2
And so on.
(Obviously "Track 1" and "Track 2" are just placeholder names in my example just to show what I mean.)
I've use this method since day 1 of Apple Music and has always worked and avoided a lot of mismatched album artwork as well. (Just took a ton of time when initially setting up my 7700+ song library.)
The way I have been doing it for some time is by changing the 'artist' and 'album artist' into 'Ndfkfpgitntbdtdsrwvdebfnfjtptopmhjdhdeg' before loading an album into iTunes. Then I upload it. And when it is uploaded I change it back to the original artist. This method has not failed me yet.
I wouldn't wanna even try that..... quality loss aac is still lossy regardless is u convert from one lossy format to another lossy format.... it may not be different format per say, but its still a conversion. You taking it and re-creating..