Glad you managed to do something about it, because it was bothering you.
If I may add my 5cents: I got one of the caviar minis, the last ones they made, in 2018. Mine had perfectly EVEN sides to begin with and became totally uneven after being used a lot (never overstuffed though). I could not care less because its nothing you can see from the front or back, and who is gonna compare the sides of my bag!? except me?
I want to say its not "a shame you had to do this", because, think about it: HOW. just HOW. is natural leather supposed to remain EXACTLY the same if its not forced to stay in shape by stitching, glue, or a supporting lining? The mould it forms on the sides of the mini is not "PRESSED" into the leather, it cant look exactly the same. do you know what I mean? I own 3 chanels now and none of them have identical twin sides. I think thats too much to ask. Chanel is luxury but even they cant perform wonders on leather and make it do unnatural things. leather lives. itll change a million times over by the time u have used this bag for a few years to come. What you have pushed in now will pop back out - you can repeat the process but it wont stay that way unless u stop using it.