Depends. There's certainly the opportunity to reduce Q a bit, but not as much as you'd think, and not everybody exploits it. For example, the SRAM X0 3×10 actually has lower Q (by 0.5mm) than the X01 1×11
If they fit your frame, the XX1 narrow-Q version is 156, which is halfway between the ~145 or road cranks and ~168 of most ordinary MTB cranks. You'd have to find the current position pretty annoying to want to spend £300 on new cranks.
Depends. There's certainly the opportunity to reduce Q a bit, but not as much as you'd think, and not everybody exploits it. For example, the SRAM X0 3×10 actually has lower Q (by 0.5mm) than the X01 1×11