Pulsing the LED at 50% is a bad idea because it produces a great EMI noise that can perturb your receiver so it can be a great danger. Beside this the LED don't get to critical temperature because during flight you have a great cooling system with the air that pass your plane. And even you landed you have at least 1 min to reach a dangerous temperature of the LED so plenty of time to turn it OFF. Anyway all this parameters depends with the power you apply to the LED and the size of the heat-sink of the LED and you can test all these on your lab. You can simulate the cooling of the air with a blower or a fan. Isaac did all this tests so he knows exactly that during flight is no problem of overheat and at landing he has couple of tens of seconds to turn it OFF without any danger of overheating. Also the power supply of the LEDs has integrated a auto-reset fuse which will cut the current in case of passing 1.7A of current consumption. So in case of possible broke of the LED most probably the current will climb up and at the end the fuse will disconnect the power supply.

Any other question regarding electronics of this project you can ask on this forum or using my direct email [email protected] or [email protected]
Thank you for your interest
Sorin
YOARDUTECH