I found that on my Proforge 3.5 the servo ground wire was connected thru the add-on relay. The servo motor was trying to send current backwards thru the signal connection. This caused the servo motor to heat up and stop working during the ARM_INSTALL macro.
I Bypassed the relay (out of the circuit) and ran the ARM_INSTALL macro which left the servo motor power on for 24 hours. The servo motor was cool, as it should be. The servo connection on the BTT SKR 2 board matches the connector on the servo motor, ground, power(+5), & signal, Brown, Red, & Orange.