ANSWER: Good practice, no harm.

We often reassign address or LED lines for devices to simplify PCB topology. When doing so with several numeric LEDs, its wise to pick one pattern and stick with it so you don't require a different table for each digit.

Some people mix the lines on external EPROMS to make it harder for reverse engineering but that's usually more trouble than its worth.

You do have to be cautious when mixing address lines on chips that have block commands like some parallel FLASH. You could find that you've erased or locked a disjoint block if you're careless.

aka j