I’m located in zone 5 northwest Ohio. I have a 2 story house. In the county on a hill so I get a fair amount of wind. The drywall is off so this is basically new construction.  I’ve received multiple quotes from insulation contractors. I have 2×6 walls with 2 sheets of 1/2 osb on the exterior. I’m not sure why the previous owner did this but it is what it is.
One contractor wants to spray foam 1″ closed cell on everything then go back and wet cellulose the rest of the cavity. I asked about moisture problems and he said” I’ve been doing this for 13 years with no call backs”
#2 wants to just spray stabilized wet cellulose everything. With 2″ closed cell on the sill plate.
#3 just wants to spray 3″ of closed cell spray foam in the cavities and 2″ around the sill.
#4 wanted to just spray foam 2″ closed cell spray foam from the sill plate all the way to the roof peak for an unvented roof…. I did not like this option since the low R value of only 2″ and the hot roof deck.

I’ve tried finding actual studies on the stabilized cellulose. The only one I found was one done on a chicken coop. After 7 years there was minimal settlement. I’m still a little Leary about it settling and having a couple inches of air gap at the top of my walls after 10 years. Also I’m planning on living at the house for 40+ years so I want to do it right now. I’m just looking for some input on my 4 options.  My main concern is just moisture and mold in the wall. I’m ok will paying a little more on heating and cooling cost. Since spray foam is around 7k more.  I’m not sure I’ll re coop that in savings given the R values are compatible for the amount of spray foam I was quoted. Unless cellulose degrades quite a bit after 20 years.