The simple answer is no. From what I remember its just meant for diagnostics and loading indications. Sorry I forgot all the details but it may be the teensy 4 beta thread.
The T_4.x RED LED on the 1062's (diff color on Teensy MicroMod) is only controlled by the bootloader chip, nothing from the main 1062 MCU can control it. If the RED LED is not dark, the bootloader MCU chip is in control.