No you can't cash out of a multi early. Although multi bets consist of multiple events or matched. It is still considered as a type of single bet. After a bet is placed you must wait for the conclusion of the event from the last leg that the multi has been placed on.
Once the results of the event or match have been posted we will automatically provide an update on whether your multi is successful or not. Subsequently, if there is any payouts to be made they will be automated and done once the final results have been verified.