Everything about this change looks like a bug and things we are doing to get around it are workarounds until they make it back the way it was.
True, we can double click on it to change the length, drag it, etc, but you can do this will all other transitions on top of working with the effects panel where we can simply scrub the length of time precisely to what we want, rather than guessing, or double clicking into it and typing it in.
I really hope they change it back. That tab looking thing is very unintuitive and does nothing.