Hello,
I am in Zone 6 and installing a wood-stove this week and planning the exit through a vaulted vented 2nd floor roof. I am looking for ways to insulate around the exit and what to do about the air gap. The assembly is (See pic also):

Installed:
1) Asphalt shingles
2) Ice and water
3) Advantech roof sheathing
4) 2×12 Rafter (inside the rafter opening is):
-2″ air gap
-2″ EXP with spray foamed seems
-8″ Mineral Wool
To be installed:
5) 2″ Poly iso taped
6) Strapping
7) Gypsum

Also wondering if I can frame in a box through a rafter so the pipe is where I want it, or if I am better off moving the stove(see 2nd attachment).

Thanks for any suggestions & resources.