While neutrals can't be doubled up, grounds can
So which is it?ONLY for neutrals/grounded conductors
Not that I'll have an issue with neutral holes but just for reference.
Just spitballing here but it seems they would provide a way to separate the left and right neutral bars.
So you wouldn't have to add a ground bar when doing a subpanel.
I think there are some like that I've seen before. Maybe a GE panel, I don't remember. But one had a flat bar that tied the left and right.