My tool of choice for prodding at things over SPI would be a Bus Pirate, but I don't think it'll do you any good in this case.
Yay progress! Boo problems What other interface modes does the breakout support? I've got an LCD hooked up to my Pi with SPI and it runs just fine, especially for emulating a calculator.My previous LCD, controlled by an ILI9341, was broken out on a board that only provided an SPI interface, whereas this one provides a 16-bit RGB interface. I remain slightly hopeful that I might uncover SPI commands that will allow me to specify an SPI data mode. Is anyone familiar with a minicom-like application for talking to SPI devices, hopefully with the ability to set a clock speed? I guess I'd also have to be able to poke other GPIOs.