3rd row in a 206

A couple quick questions about the third row seats in a 206. In
pictures, the rear of the fuselage looks to taper down pretty quickly
aft of the trailing edge of the wing.

What kind of vertical and horizontal room is there in the 3rd row?

Are these just child seats, or could smaller adults sit in them
upright?

If one of the two were removed, is there a little room for luggage?

As a note, I'm 6'3" and 270', my wife is 5'11", and, although my 3
kids are small now, I think they will grow tall.