Set beat me to it :)

The index will also contain nodes that are not visible to this
transaction because of the mga. I can not answer how intelligent the
skip is though. There may or may not be room for improvement. But as
has been discussed at length in other postings, adding version
information to the index node would bloat it to the point where the
index would itself take up more space, then your index access would be
slower and the whole system would suffer in other areas.

Adam.