I've been running Gurjon's zip and was playing with sign post files. I was able to get them off the right side so they don't cover the compass and other bmps as well as decrease the height so it doesn't cove half the screen.
I modified the laneinfo signpost ini from the standard 3.0 data zip for someone to try out and report how it works.I can't test it since I'm running gurjon's zip and I don't use the emulator.
Edit: See IDT's message below for how to shrink the signs for Avic type zips. Changes I made to the Gurjon zip to shrink them will be posted hopefully before the weekend.