Is It Possible To Select Specific Train Set Numbers In Tsw?

so i was curious about something about the scenario designer and customizing the workflow in scenearios.
i watched tutorial videos about those and i have noticed one thing.
apart from being able to select which formation and which type of train youre able to set in customized services. You dont seem to be able to select that train type you selected's train set number.

Is that already a feature? Or it isnt and is yet to be added to the game? if it isnt in the game yet, has anybody suggested this before?

 

Nope it’s random what unit you get

 

Wish DTG would add this. Would make my scenarios so much easier to make.