Should non-tree-abiding pseudo elements have a separate IDL interface?

[danielsakhapov]

Full context: https://github.com/danielsakhapov/CSSPseudoElementDoc?tab=readme-ov-file#31-non-tree-abiding-pseudo-elements

Description:
CSSPseudoElement is only defined for tree-abiding pseudo elements.
Should we add support for non-tree-abiding pseudo elements? E.g. for a hypothetical getBoundingClientRects() for ::selection? Should CSSPseudoElement be enriched with new methods or should new specific interfaces be added?

Recommendation:
Based on some discussions in web animations, non-tree-abiding pseudo elements should likely have a separate interface that is not inherited from EventTarget, as it’s not possible sometimes to fit it into e.g. a bubbling model of events.