[southwindcg]

Specifically when produced with "exceptional purity"...

Wikipedia [0] lists room temperature thermal conductivity at 1300 W/(m·K) and says "Chemical synthesis of cubic BAs is very challenging and its single crystal forms usually have defects." I guess it remains to be seen how cheaply and easily this "exceptional purity" can be achieved.

[0] https://en.wikipedia.org/wiki/Boron_arsenide