It would be nice to be able to decide if when opening a folder for message view you want to start at the newest, oldest, or oldest unread.
g/G jump to top/bottom, does that work? (Double keystrokes for gg aren't easy.)
Seems like there should be a button for next/previous unread. Does J/K work for that? That would give you a GK to reach the oldest unread.
I think j/k for up down and g/G works. I don't traverse the tree by next unread. I just find it annoying the claws always starts where I don't want it to.