I confess that I'm not a huge fan of exploration - I'll do it as part of, or coincidental to, CG's or missions, but never for its own reward, and always slightly grudgingly to salve my ODC-need to 'get them all'. Alas, overall, I do find it a bit tedious (sorry).
What would improve it for me:
1. Instant on-screen (or better yet spoken) feedback on the analysis of the scan - e.g. composition, atmosphere, radius, mass, gravity, whether landable, bases
2. Easter-eggs on (landable) planets reported by the detail scanner - e.g. crashed ships, lost alien tech, or large deposits of rares - with their rough location(s) shown from pre orbital cruise
3. The ability to sell information I have (had to) buy - just seems logical, given it's the same data I would have got had I scanned, rather than paid for, and either way it's info the buying station doesn't have - I fully appreciate I'm flogging a dead-horse with this one...
4. An automatic percantage recorded (on the system map? togglable?) showing systems I have passed through but completed less than a full scan - e.g. when running a mission I often don't have the time survey the systems I pass through, I may do a boom to see what's there whilst fuel scooping, but not delay to scan each body
4.1 ...or the ability in the navigation map to plot a 'reverse route' - yes bookmarks may help, but I'd rather this was auto-magical
5. A much more free-roaming camera, for much improved 'selfies' - perhaps even an auto-cam giving fly-bys...
6. BB missions specifically requiring exploration data for their completion
7. 'Select optimal survey route' in a system, where the nav computer works out the shortest overall route to visit all of the bodies - heading to the next-nearest body may not be the most efficient
8. (and even I'm not 100% on this) but a 'find me fuel' shortcut, which locates the nearest source of fuel (station or scoopable star) and plots a course - or it provides you with the number for the fuel-rats if you're already stuck
Sorry, I rambled on more than I expected... food for thought...

What would improve it for me:
1. Instant on-screen (or better yet spoken) feedback on the analysis of the scan - e.g. composition, atmosphere, radius, mass, gravity, whether landable, bases
2. Easter-eggs on (landable) planets reported by the detail scanner - e.g. crashed ships, lost alien tech, or large deposits of rares - with their rough location(s) shown from pre orbital cruise
3. The ability to sell information I have (had to) buy - just seems logical, given it's the same data I would have got had I scanned, rather than paid for, and either way it's info the buying station doesn't have - I fully appreciate I'm flogging a dead-horse with this one...
4. An automatic percantage recorded (on the system map? togglable?) showing systems I have passed through but completed less than a full scan - e.g. when running a mission I often don't have the time survey the systems I pass through, I may do a boom to see what's there whilst fuel scooping, but not delay to scan each body
4.1 ...or the ability in the navigation map to plot a 'reverse route' - yes bookmarks may help, but I'd rather this was auto-magical
5. A much more free-roaming camera, for much improved 'selfies' - perhaps even an auto-cam giving fly-bys...
6. BB missions specifically requiring exploration data for their completion
7. 'Select optimal survey route' in a system, where the nav computer works out the shortest overall route to visit all of the bodies - heading to the next-nearest body may not be the most efficient
8. (and even I'm not 100% on this) but a 'find me fuel' shortcut, which locates the nearest source of fuel (station or scoopable star) and plots a course - or it provides you with the number for the fuel-rats if you're already stuck
Sorry, I rambled on more than I expected... food for thought...