I’ve found that you don’t need to go into the leaderboard itself to see which ones are dirty vs clean. If you go into Rivals and select the class you can scroll through the tracks and your next rivals time is pictured on the track. If he’s dirty your dirty, if he’s clean chances are your clean. You do need to go into it to see your time and place but this works as a quick way to see if you’ve posted a clean time, without loading the board.
Any time other than those achieved tuning in the test drive feature count for LB times.
The link provided didn’t really answer your questions…