Either way you have to test it with the expected screen shapes, which is easy by making custom resolutions in your Game window. This lets you test anchoring and scaling and parenting and grouping to get what you want.
Here are some notes on UI Anchoring, Scaling, CanvasScaler, etc:
https://discussions.unity.com/t/845782/4
https://discussions.unity.com/t/848795/5
Unity animations can change just about any public property, regardless of what it is on.