I am replacing kitchen counters and planned on removing the tile back splash and plaster between the upper and lower cabinets to update the electric prior to installation. Walls are plaster furred (3/4 to 1") out over block above grade. I also think they may be some kind of half hearted balloon framing because the seems to be a lot of air infiltrating from the attic. I would love to gut the walls floor to ceiling but that is not an option. So my question is would I be doing more harm than good attempting to partially insulate the wall cavity while its open with something such as spray foam? Open to any other ideas as well. Many thanks all.