Operating system: Kubuntu 18.10, 4.18.0-22-generic #23-Ubuntu SMP Tue Jun 4 20:22:46 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Graphics card: NVIDIA Corporation GP106 [GeForce GTX 1060 6GB] (rev a1)
Broken: 2.80, 9c5d54bfaf48, 2019-06-08 13:24
If I change the Scene's Unit Sytem for rotation between degrees and radians, the graph editor curves update accordingly in relation to the graph editor Y axis. Manipulation of points in the graph editor also works as expected (e.g. selecting a point and doing "G Y 1 enter" adds one radian or degree, as appropriate.)
If I change the Scene's Unit System for distance from metric to imperial, the curves do not update -- they are always in meters in the Y axis of the graph editor, and manipulation of points in the graph editor is always done in meters ("G Y 1 enter" always adds 1 meter, not 1 foot, as expected.)
Same issue is present for e.g. animating the "Gravity" parameter of the scene, which is in m/s^2 and always displayed in reference to meters in the graph editor, regardless of selected Unit System. I suppose there may be other examples as well.