Cache invalidation stratergy

I'll repeat my question from the earlier issue:

It seems like Drupal Core should realize that any change in formatter settings that is part of the view mode being used to display the field, or the view that it's part of, should automatically invalidate the display. If that isn't happening, it's a core bug. The individual field should not have to invalidate the cache when formatter settings are updated... should it? Do other fields do this? I don't think so... The formatter settings are saved as part of the view mode or view, and that being changed should invalidate the cache behind the display.

I think this may just require some manual testing to verify it is actually a problem.

I chatted with entity/field/views experts in Slack today about this. Our module should not have to do anything to make this work correctly. It should be true that:
- If you edit a View by changing the field display settings using any field formatter (such as ours), and save, any page displaying the view should have its cache invalidated, so if the page is viewed again it should be recalculated.
- If you use Manage Fields in Field UI to edit the display settings for a field formatter (such as ours) and save, any page displaying with that view mode (teaser, full page, or whatever you edited) should have its cache invalidated, so if the page is viewed again it should be recalculated.

If that is not happening, we should open a Drupal Core issue about it. But our module should not have to do anything special to make it happen.

Accordingly, I'm going to close this as Works as Designed... if you can find a case where this isn't happen, please provide steps to reproduce and open a Drupal Core issue.