Intercellular airspace and plasmodesmata contact and diffusion

I think it’s worth considering that less contact with intercellular airspace (IAS) means more contact to other cells.

At a constant density of plasmodesmata, more area in contact between bundle sheath (BS) and mesophyll (M) cells means a greater total number of plasmodesmata between cells. This should increase the conductance of metabolites between BS and M cells, which should increase the efficiency of C₂ and C₄ photosynthesis.

Conversely, a greater access of BS cells to air would increase the rate at which CO₂ leaks out to the IAS.