If i disable a component in canvas, does it calculate everything again in that Canvas?

I found out in UI optimizations that we should use a separate Canvas for things that are changing and another Canvas for static stuff, so that they don't have to calculate the static stuff again when some UI element changes in the other Canvas.
So for a menu system, is it better to use multiple canvases and enable/disable them or use multiple panels within same Canvas and enable/disable them?

 

Did you find the Fill-rate, Canvases and input document in the Best Practices section already?

You probably find the "UI Canvas rebuilds" and "Splitting Canvases" sections interesting.