Yes, sure ESP8266 is NOT 5V tolerant by design. I would only say that there are some modes of operation where the device can withstand out-of-specs overvoltage condition without a failure.

I choose to power the LED strip straight from the ESP8266 5V pin of the board, powered from the USB cable. It’s 300 LEDs in total and I was pretty sure that, even without doing the math, it ...