What property orthagonal to thermal diffusivity?

Factual Questions
1

Thermal diffusivity is a property of a substance that determines how quickly conduction moves temperature changes through it. This property has units of area per second and is usually calculated as the thermal conductivity divided by the volumetric heat capacity.

Is there a name for thermal conductivity multiplied by volumetric heat capacity? In the space of conductivity by capacity, this property would be on the axis perpendicular to diffusivity. It would represent how quickly a substance could transfer heat with a source or sink when that substance was a thermal reservoir.

2

When doing a unit check, it becomes pretty obvious that W/(m K) / (J/(m^3 K) becomes m^2/s, like the OP states. However, W/(m K) * (J/(m^3 K) gives J^2 / (m^4 K^2 s), a derived unit that I am not familiar with. The only time I can specifically recall using M^4 is in moment of inertia of beams. This doesn’t answer the OP’s question, but perhaps it’s a start to determining the answer?