This is a sub-issue of #1910606: Improve the configurations schemas for Views significantly.
Problem/motivation
#1866610: Introduce Kwalify-inspired schema format for configuration introduced some config schema coverage for views and #1910606: Improve the configurations schemas for Views significantly extended it, but it is not complete. The changelog leads to (hopefully extensive) documentation on the format at http://drupal.org/node/1905070. While there are little cleanups planned for the format overall, the current format is a result of months of back and forths, so it should be perfectly fine to apply it more widely to core.
Proposed solution
Figure out the missing pieces that are not yet covered. Write schema file sections for them. Clean up / fix any issues in current schema.
Create a configuration schema for missing view display extender plugins
Schema in place
Please refer core/modules/views/config/schema/views.display_extender.schema.yml
Schema not yet in place
Basic.php
InputRequired.php