I am wondering about that external I2S codec chip. If the Wt32i firmware isn't careful enough, or if perhaps the settings being used result in it enabling its outputs, then that chip could be driving voltage onto the I2S pins. Fighting the empeg voltages. Uh oh.

That could result in a very hot chip, a fried chip, or perhaps fried I2S outputs on the empeg too.

I think I'll just cut the I2S traces to/from that chip on mine before hooking them up to an empeg.
Or do what you did and just get rid of the darned thing.

Kinda surprising the dev board lacks jumpers to disable/bypass the chip.