Problem can be that padding doesn't control slosh while skiing, so while the boots feel good on, the feel of skiing with them can be awful.this is a similar problem that I have. My bootfitter increased my last to 102 to increase the height because unfortunately those two things correlate. there is not a way to increase that on its own (at least according to this guy). he will add padding side to side before they heat mold them to keep the toe locked in to help control skiing. But honestly, the 102 last felt glorious. my toes weren't numb after twenty for the first time ever because there was the room top to bottom.
I definitely got vertical toe height in my very narrow lasted boots, so while the two are correlated It's been my experience the verticle toe space can be increased through stretching the shell.