Unable to override validation logic for custom component

[aarpyy]

I have been unable to find in documentation or through looking at source code how a custom component can override validation logic. I'm opening this as a bug because Issue 4129 on this same repo opened this same issue as a bug with no response. Issue 369 was opened on the react repo and Issue 594 was opened on the angular repo, all for the same exact issue and no response.

I would greatly appreciate anyone's time and effort pointing me in the right direction, as I am largely unable to create the components I want without custom validation (the level of which I cannot do in the custom field in the schema).