Your competitor says that BST detectors were designed for imaging applications while microbolometers were designed for radiometric applications?
All thermal imaging detectors (whether it be VOx, ASi, BST, MCT, InSb, PtSi, GaAs) were all designed primarily for thermal imaging applications, as this is the largest market. It is then the challenge of the infrared camera companies to mathematically convert the thermal information into temperature. Technically, there is no reason why a BST sensor cannot measure temperatures with the same accuracy as microbolometers.