I just got the Flex board today, with a handwritten thank you from @arvydas and a very nice UK postage stamp.
Still waiting for my RGB strips to come in from another supplier.
My main question I guess is the pin outs on the Flex board - SPI is different in that it requires a clock line.
What about the power consumption running 32 leds at POV speed over SPI (will USB handle this, or do I need external power?)
I shall experiment with the firmware (likely adding an extra mode for SPI) and post back with any results.