Someone posted in the discord group that it broke their S9J and they had to send it back to bitmain.
Are you sure?
S9j??
I rather believe it was a T9+, but anyway, why should it break with our software? You exactly know, that changes in the shell can easily set back to default.
I testet it with several miner types: e.g. I flashed D3 firmware on my X3 and A3. Sure, did not work, but when flashed the original FW from Bitmain´s download website, the miner was like "new".