If it works as is I guess leave it, however as you point out it might be nice to control the entire board with 2 pins so I'd be inclined to go that way. For that matter use a 16-bit IOX (like the MCP23017) and you still only need 1 chip.
I've often thought of using these displays but they are SO expensive I can never justify them. The best price I can find right now if about $16, hav eyou found a cheap AND reliable/continuous source for them?
Rob