Before Alpha 3, it was possible to build brakes on hills/curves. This added more realism as most coasters have their brake-runs on hills to allow gravity to pull them down the hill. Also, coasters use trim brakes during hills to control airtime.
This reddit post has more detail about the suggestion: https://redd.it/51jxxz
This reddit post has more detail about the suggestion: https://redd.it/51jxxz