The issue focused in the end-to-end two-way call, and TKG is a V2V (in 2-way) with an I2C "P3" BLE PX0.1/1.0 baud.

BZ7=5+4(8)*2(6)TKG(4)&(1)&(0)&(0)&(0)&(0)&(0)&(0