To my untrained eye it doesn’t look like a ESP8266 and I have no clue what it is.
I’d really appreciate if anyone recognizes this microcontroller and can share some wisdom on whether this thing could be flashed with Tasmota or any other custom firmware.
The ESP board is the blue daughter board with the metal shield. Look for programming pads (tx,rx,gnd,3.3v) on it. You will also have to trace out the connections to the base board to work out how it is controlling the LEDs. The 16 pin SMD chip could be anything. The part number appears to have been ground off.