I couldn't do this in a private lobby online, nor do i even have any money in MP to buy Are you saying you can customise online character model clothes with enhanced native trainer e.g change t shirt and trousers, or access the new ill gotten gains clothes?
The important thing here is having a mode where mods are allowed to be used and i can access MP character. So you can use mp character in director mode, but not be able to change into different clothes from the huge amount of choices including the new ill gotten gains clothes, right?