This should fixed in #19449 with the separation of as and components

Out of curiosity, did we ever make a final decision on @default vs. @defaultvalue vs. @defaultValue? I think there was some problem with using @default with TSDoc.

The last I heard last month, it was still open for discussion in the v-build team: #19271 (comment)

No idea tbh, I don't think it really matters until we decide to stick with one officially.

Ditto

Rather than extending BadgeProps directly, what do you think about having each badge define its own Slots and Commons types that equal or extend BadgeSlots/BadgeCommons?

export interface CounterBadgeSlots extends BadgeSlots {}

export interface CounterBadgeCommons extends Omit<BadgeCommons, 'appearance' | 'shape'> {
  // ...
}

export interface CounterBadgeProps extends ComponentProps<Partial<CounterBadgeSlots>>, Partial<CounterBadgeCommons> {}
export interface CounterBadgeState extends ComponentState<CounterBadgeSlots>, CounterBadgeCommons {}

I just don't see a need for extra types at this point, is there a reason it would be better to have separate types ? is it for API consistency ?

The CounterBadgeSlots type is purely for consistency. It could be left out if desired.

The other half of my suggestion is to have CounterBadgeCommons extend BadgeCommons, rather than having the Props/State types extend the base badge. That makes it so you only need to use Omit for 'appearance' | 'shape' once, and it seems more logical to me, at least.