In the Timeline in-line curves...
When manipulating a single key, everything is fine, but when manipulating multiple keys, curves & keys flicker when manipulating them. See attached gif

Steps to reproduce:
1. Open attached "TimelineFlickerRepro.zip"
2. Select "CubeTimeline" asset in the Project Window
3. Zoom into the Timeline until you can see individual frames
4. Select multiple animation track keys including the last keys in the track in the Timeline Window
5. Move the keys around

Actual Result: curves and keys flicker
Expected Result: no flicker and precise update of curves and keys during manipulation. Exactly like when manipulating a single key.

Reproduced on Unity versions: 2019.3.3f1, 2020.1.0a24
Reproduced in Timeline package version: 1.2.11
Couldn't reproduce in Timeline package version: 1.2.10