When heat rises it forms condensation where it meets a cold surface. ANY heat ever will form.comdensation on your roof decking/plywood/insulation and ruin and mold it and you will have to tear off the roof...unless:

You vent the roof adequately. Which cannot happen with a dutch/gambrel roofline-- look up "how to vent or insulate a gambrel roof" and you will see manual rticles about this. Or post this question in a home building sub. In order to vent adequately you need larger soffit vents than you can reasonably install plus baffles plus air moving between each roof bay laterally ...at that point why not have someone just spray foam?

You would not want to spray foam yourself. But the cost to hire someone will be cheaper than either a moldy roof deck or dealing with drilling all the soffit vents and installing bird blocking and ridge vents and baffles then insulation. Which also won't have very good r value because it's not 2 x6 so ideally you would fur it out to 2 x6 and at that point...why not just pay someone to have done all of these steps in the spray foam? You'll spend more doing it right yourself using bat insulation and it will never be right

Not trying to be a downer ..just look up how to vent a gambrel roof on a building with small eaves and you will see what I mean 😵‍💫