My 1950’s bungalow in climate zone 4 has plaster coved ceilings on exterior walls.

From the attic you can see the top of the wall’s foil backed fiberglass insulation poking into the cove area.  The cove area it self has loose fill fiberglass sitting on top of the wall insulation up to the top of the ceiling joists.  There is no air sealing of any kind.

I’m in the process of improving insulation and air sealing the attic.

My plan is to make sure the top of the wall’s insulation foil vapor barrier is pushed against the interior side of the cove, fill the cove area to the ceiling plane level with fiberglass batt and then air seal by foam sealing a piece of drywall or foam board over the top of the cove area at the ceiling plane level.  This can then be insulated along with the rest of the attic.

Any thoughts on that approach?