Alot of thought was given to tinkers/hacking.
Jeri has pics on her site of her prototype and it's got all sorts of extra bits that Tulip didn't put on, I guess for reasons of cost. There's a place (solder hole deals) for a second joystick port on the final product, just not the connector itself.
Seems to me like a dream job for someone like Jeri, being ASKED to make this device, so she used her knowledge to make something cool and also put in some cool stuff for hackers and retro-geeks...all of who(m) she probably knows personally. :-)