I don't think that's an issue, as long as your foot doesn't move in the binding.
If it moves around @ all. NO GOOD
If it pulls it over & that's where it stays, change the angle of your bindings 1 degree to compensate
I have 9's & before the reduced footprint all Burton Larges fit. I have about 6 pairs of L, none fit.
Now I have to use Mediums. For me I can't adjust the straps small enough.
I betcha mine are worse, they have to be?
Never really noticed the amount of space though because my boot never slides around.
Mine doesn't slide around in a 9, yours shouldn't
in a 10.5