Is it possible to get it to meter using the selected AF point instead of the center of the frame?Nope unfortunately not thats the realms of 1D bodies only
I know it's not supposed to be able to do that, but sometimes it does. For instance while sitting in a dark room and shooting down a well-lit hallway, it meters down the hall way with center AF point, but meters for the room when using the right-most AF point (on wall of dark room).
5D Mk III, Elan 7e, Fuji X-E1, some old rangefinders
Tamron 24-70 2.8 VC, Canon 70-200 f/2.8L IS II, 400mm f/2.8L II, 100mm L IS Macro, Sigma 85mm, 50mm, & 35mm f/1.4's, Rokinon 14mm f/2.8, Canon 2x Extender II, Kenko 1.4x, 430 EX II, Elinchroms