Having looked at the data sheet, my original idea won't work. There might be enough space to put a pcb with a chip on it between the card housing and the bend to meet the main board, but there certainly isn't enough to put a board with two chips. However....
I got to thinking about this. Assuming you cut the connector pins right at the bend, and cut the pins back a little on the connector side, it -might- be possible to use through holes for the vertical pins, and pads for the horizontal ones. This would allow you to mount the mod board off the end of the card connector (eliminating wired connections) IF there is enough empty space behind the connector. And, if the bus switch chips are on the bottom of the board, it shouldn't have the problem of sticking up too high.
Just my 2 cents. Would be neat to see, though.