In addition to what Tom said, I see a lot of your numbness and lack of sensation in your toes associated with your combination of a "super high" instep with a low-ish volume boot. The SX 120, while it is a 102mm boot, it is one of the lowest and narrowest 102mm boots on the market, if not the lowest/narrowest.
I totally understand that you like the snug fit, but if the instep of the shell is too low for you, then it is harder to fix than width, in my opinion. It will lead to decreased blood flow and numbness for sure.
Your boot-fitter can try grinding down the boot board a bit, but the one that is in the SX isn't very meaty so not a lot of improvement will be made...
If improvements cannot be made in the numbness department, be prepared to come to terms with the potential that this shell might not be the best match with your foot. If that does end up happening, there are other boot options that will be a similar width, heel fit, and flex but with a more generous instep height.