Didn't we all assume LEDs were just cosmetic until they crashed a system? I've been down that road, and craig.pat's multimeter tests are spot on. My last build had a dozen addressable fans, and under load, the 12V rail dipped to 11.3 volts, causing random resets. Took me weeks to diagnose because I blamed everything but the lights. Swapping to a higher wattage PSU fixed it, but the lesson was clear: those peanuts add up. Now I always budget extra headroom for RGB, no matter how trivial it seems.