I found a forum post from 2015, although I don’t believe this works. Is there any imp API’s to disable these LEDs?
Sort of. On impOS 40 and under,
imp.enableblinkup(false) will disable BlinkUp and the status LED at the earliest 60s from cold boot, depending on when you call it. However, under the upcoming impOS 42, calling
imp.enableblinkup(false) will disable BlinkUp and the LED immediately.
See imp.enableblinkup() in the Dev Center.