I say get rid of hole signs altogether.
I would prefer a tablet computer on each tee that gives the official yardage, a hole flyover, GPS offering distances to multiple hazards, tips from the pro on the best strategy, a beer-cart pager that allows a group to call for service, and a food menu that allows players to order from the turn in advance. The tablets should also have games and other apps installed that allow groups to pass the time while waiting for a slow group in front. For that matter, they should include a feature that sends messages to the group ahead that they can read when they arrive at the next tee's tablet, like "While we're young!" or "Nice putt on 6!"
The tablets should also have an app that players could sync to their phones and use in place of a scorecard. This way, multiple groups playing in a game together could track scores in real-time either on their phones or at the tablet on each tee. Club-level tournament golf would benefit tremendously from real-time scoring as well. Other basic functionality should include a weather tracker with radar, easy access to stream live PGA golf along with college and pro sports telecasts, and easy access to take Vines of the swings and antics of playing partners.