Might be nice when you run the discovery scanner on an object, if it's not yet registered against another CMDR, the game told you there, so you know you stand to plant your flag if you get the data back. I believe you instead need to go and look in the system map to find this out.
How about a heatmap that shows frequency of scanned systems, but doesn't actually show which individual systems are scanned for each single star?
We're selling our data to coorperations and governments, they wouldn't likely just throw their info out there for all to see. Added to that, they seem to need multiple scans of a system for satisfactory data, so it would even work against them.