Hello Bearcat,
I've tried to restore with original Netgear firmware but it doesn't work.
For XPEnology, I've boot with USB key in front of the NAS.
My computer has detected the NAS with Synologi Assistant over the network.
He asked to do an installation, I did OK
Then he asked to restart the NAS but nothing.
I tried again to connect with the USB key but without success.
However, the link you give me, explains how Install XPEnology on a standard computer and not on a NAS