Hello!

We are re-roofing our house in Western Massachusetts this year. As we have cathedral ceilings, it seems like a good time to consider anything we can do to give ourselves better insulation in our 2×10 rafters.

What we know/think is likely:
– 2×10 rafters
– Currently insulated with fiberglass (unsure if faced or unfaced)
– Possibly a poly vapor barrier on the interior side (this is the case for our walls, so I imagine maybe the same here?)
– Vented assembly with ridge vent and (I think?) soffit vents – these basically look like mesh along the eaves
– First floor family room has a tongue and groove ceiling; unsure if there is drywall above this but my guess is no

Some issues we notice as things currently stand:
– Mold/mildew growth at the peaks of the ceilings when we bought the house
– Very hot and stuffy on the second floor when it gets warm out

Most of what I’ve been reading goes about retrofitting from the inside out (spraying foam from the inside to the underside of the roof deck). We will not be doing this as we’ll be re-roofing and it makes the most sense to address this from the outside in. Open to other thoughts, though!

I’ve been researching and as I see it we have a couple options:
1. Keep vented and do ~7″ of closed cell spray foam, spraying from above on top of the ceiling 
2. Convert to unvented and fill in the bays (details below) + put 4-5″ of rigid foam on top of the roof deck
     – Fill with blown in cellulose OR
     – Do some combination of foams/fluffy insulation/rockwool (this would involve taking off the existing roof deck, which I don’t believe would be required if we did the blown in cellulose)

I imagine #2 is a lot more expensive pretty much any way you slice it than #1 given the extra labor involved with raising the roof that much, but am not sure (and would love to hear thoughts).

Do both of these options seem valid from a building science perspective? Are there any decent options I’m missing?

Thank you!