An upcoming feature we are working on is Online Time Trial.
Like in normal Time Trial each player races alone on the track vs the clock. But since it is a network game you can also see other players as ghost balls. Not just ghost ball replays but live ghost balls.
Since there is no interaction with other ghost balls (no collisions or slip-streaming) all times can be posted to the same leaderboards as for single player Time Trial.
Each player is free to start or abort their race attempts at any moment without interfering with other players. (Just mind that when the host leaves, everyone is disconnected.)
For a combined race and Time Trial attempt anyone interested just needs to check “Auto-start next interval” and when the interval countdown reaches zero all players will start simultaneously.