This hadn't occurred to me until I read more of the PiBakery source.

Another option for getting convenient console access is to configure the USB OTG port in target mode as a USB serial interface. In PiBakery, this is the "OTG serial" block.

This only works if you're not using the USB port for anything else, which means you're using a Pi W's WiFi to get network access. If you're using the OTG port for Ethernet or WiFi, then this isn't an option.

In principle, what this means is that once this is set up, you could just plug an ordinary micro-USB cable between the OTG port and a host and the host would see a USB serial interface show up. Open that port with terminal emulation software and you'll get a login prompt.

EDIT: I tested this out and, sure enough, it works great!