I pray to God those trims aren't turned on...
To be honest i dont think they will be, I think their primary purpose will be to make sure the train has enough speed to go through the cobra roll, also if you look there are catwalks at the side of each bunny hop so maybe they will be used to stop a train in an emergency, we'll have to wait and see.
If anything, it'll be the opposite to what you say.
The trims are there for a reason, the clue is in the name. They 'trim' the speed of the coaster train, they slow it down. There primary purpose is too slow the train down before entering the cobra/batwing elements.
They will no way be there for an emergency stop either. The train will be at near enough full speed at this point and they are not long enough. Let alone they have no propulsion method fitted to get the cars going again.
As the trims are fitted with ways to lift and lower, then sometimes they may be used, whilst others they may not. I suppose it'll all depend on the weather, time of day and maybe, if this coaster has a system like Duelling Dragons used too (whereas it weighs each train to find the optimal dispatch time from each lift for the best self duelling) wether or not your trip on the smiler will be trimmed or not.