Removed the straight connector for I2C and replaced it with a dual row right angle connector. One of the pins is deliberately left out on the 2x5 connector. That is because other cards that connect to the I2C bus won't use the same interrupt line as the Front Panel.
This provides a more robust connection to the Front Panel card. It is less likely to come loose and provides additional clearance down to card below (Z80_PSOC card).
Also, took apart the staggered stack-up and rebuilt it using 1/4" standoffs that are #6-32 M-F parts for the standoffs below the Z80_PSOC CPU card. Using 1" standoffs between the Front Panel and CPU cards and used #6-32 nuts at the top of the Front Panel Card. This makes the entire stackup less than 1-1/2" tall with buttons and switches at the top of the stack (Picture with taller standoffs at the bottom).
The SD Card and JoyPad cards are cabled out to external cards. Going to make a 49x49mm card which has an SD card socket. The SD card will be used with a 95x95mm to 49x49mm adapter card which will allow the SD card to be stacked easily in a mechanically sound manner. The SD card can have a right angle connector and will be routed to the Z80_PSOC CPU card. The card could be mounted on the bottom of the 95-49mm adapter card so that the cable route down but then the I2C cable from the Front Panel to the Z80_PSOC card would route down around the card. Another possibility is making a version of the adapter card with a slot on the side for cable routing.