Filtered paste: Remove all but basic formatting on paste

I realize that eventually a "Clear Formatting" feature might be added later, however, I wonder if there's a way to (on paste) clear all formatting except what is allowed by the interface buttons. I get I can "cmd shift alt v", but the specific thing I'm looking for is a filtered paste instead of just removing all formatting.

Start by tracing the editor's paste-handling entry point and compare its behavior with the formatting exposed by the interface buttons. Define completion as pasted content retaining only those basic formatting options while other formatting is removed, then verify the behavior with representative rich-text clipboard content.

Written by the indexing model from the issue text.