For all the GT2 series ESC, when 508_no_timing software is loaded for no timing sportsman event, the bottom of the ESC, with the semi-clear bottom case, will spot the RED LED is on....the RED LED is the only indication when you are using the 508_no_timing software.
If you are running any OTHER software, there will be no LED lit at the bottom until it is on throttle or brakes.
GT2 circuit board was designed way before this NO TIMING thing happened. Our next generation ESC will have all the LED indication above or on the SIDE of the ESC.