I dunno if this will help at all but I will share my experience getting a pair of silver stars that are likely from the early 2000s, mine had never been worn. For reference, I have a long narrow foot (Riedell 9.5A) and fairly skinny ankles. Though the boot was very stiff, and the foot of the boot literally fits me like second skin after a break in time, I started noticed creasing developing from where the flex notch would be back to my ankle point on both boots, apparently from bending my knees (I do not jump, I am a novice). I did a search on here and actually found some other people had noticed the same issue with the older Silver Stars, the generally accepted reason was that they just did not fit quite right. Additionally, I did not always feel like my ankles were quite right, despite the stiffness of the boot, my ankles did not feel completely supported.
I did two things that seem to have solved the problem, one, I switched my lacing technique to the kind recommended by Edea, I have seen it also called the "Russian" technique where you go over into the lace holes instead of bringing the lace under and up through them, there are several you tube videos that show how to do this. It is supposed to give more even, stronger, support. The other thing I did was get a Bunga pad for my very lower leg right above my ankle. Most people use that for lace bite I think, but I use it to make my ankle area a little larger and more "sticky" keeping the boot from shifting as much. It seems to have solved the problem, there has been no deepening of the creases, and they feel more stable.