Broken: example: 2.79
when editing multiple key frames or multiple objects at once, blender shows only the values for the active element.
When the user types "0.5", only the active object is receives the value and the rest of the selection is ignored.
This is counter intuitive and causes a lot of redundant work
Additionally, power users or animators from other systems will want to type in an expression to any value field with multiple objects selected, i.e. selecting multiple objects with different scales and entering "*=0.5" would scale all selected objects by half.
without this core feature of value entry fields, adjusting every value across blender is that much slower.
Exact steps for others to reproduce the error
1: set 100 keyframes on something.
2: in the graph editor, select all keys, "a".
3: using "t" hotkey and set all keyframe interpolation to be elastic
4: using the properties sidebar "n", set all the selected keyframes to have the elastic amplitude of 0.5
problem: what should have been one operation now must be done in 300+ operations.
note how sore your wrist gets. ;)
typing "0.5" should set all the selected keyframes elastic amplitude to that value.
typing "+=0.5" should add that value to all the selected keyframes elastic amplitude.
typing "*=0.5" should multiply all the selected keyframes elastic amplitude values by half.