Maybe because I am new, but when I am looking at stuff on the Admin page, it is a bit annoying that it isn't split where shown in the picture below.
Because I select something from the left side and it opens to the right.
As I scroll that part the left side also scrolls.
Not a big deal, but as the left is more a Menu of options available and the right is an expansion of that: the two aren't really associated.
So having them scroll at the same time is .... confusing.
Please don't use frames. They make accessibility for disabled (screenreader, etc.) a lot harder because the screenreader has difficulties to distinguish the intended order of the frames.
I don't think this is possible at all without major changes
Curious as to what resolution you're working with. 1920x19801920x1080 here and I don't have to scroll very much at all.
Also curious as to what the use case here would be for working your way down the list (other than to explore on an initial install), does one not generally just go to the page they need, and then leave?