Use Case: Side by side / before and after comparisons

[prushforth]

This type of feature is often quite useful for disaster scenarios.

[Malvoz]

In conjunction to before & after comparisons, a user might want to compare different types of map layers (e.g. road vs satellite).

[AmeliaBR]

Interesting use case. I can see a few different ways to implement it. When I read your description, I was thinking you meant by syncing the zoom and pan of two map viewers, displayed side by side. But the linked demo is probably better described as adding a custom clip path on the top layer.

This is probably never going to be something that's built in, but it's definitely something that application developers should be able to create.