How bad would it look to use counter-sunk fasteners through the front panel and avoid the whole headache? Me, I like fasteners so I don't mind it when they're exposed sometimes if they serve a clear purpose. Granted, I think I was the one that suggested using blind taps in a thread somewhere around here.
Bottom line, maybe it's worth a call to FPE to see what they think about the hole depth vs. fastener size? They're the experts.