It did indeed blow out my internal storage when I first tried it. When I went to flash, there was nothing in internal storage. None of the usually folders, most certainly not the .zip I was looking for, nothing. Enter tension.
Perhaps the next time I'll try again. It'll save a few steps. I'll have Wug's Toolbox open just in case.
Helpful hint for everyone (esp. the paranoid): get a cheap USB OTG to USB-A (female) adapter, and have a flash drive handy. Newer versions of TWRP can mount USB OTG, so it's a nice plan B if you can't get past recovery. They're cheap (<$5), small, and come in handy pretty often.