Hi Broaders!
The blink mode shouldn´t affect the APs performance in any way. Although configuring blink can be done like the way you describe it, the use case is mostly to find one specifik AP. There´s a really easy way to do it through the CLI of the controller:
# ap-leds ap-name <AP-Name> blink
# ap-leds ap-name <AP-Name> normal
one command to turn blink on for an AP and one command to turn it off :)