Rosco, I'd love to see any of the technical stuff you're worked out on that pedal setup. I've got 2 old Saitek cyborgs and a Logitech that are in various states of dysfunctionality, and have been tinkering with the idea of building either a throttle with lots of buttons, and possibly a second hat, or pedals, but have been loath to try to lay out the schematics. Other than replacing all of the hat switches and some loose connections, I haven't done much in the way of electronic repairs/troubleshooting in years.
I suspect the St90 and the cyborgs (not the EVO, perhaps, but the older ones) use the same basic board, switches, and pots. anyway, I'd be interested in seeing any of this tech stuff you've figured out.