This is especially a pain with triple-back-button focus. I have the shutter button's function set to EL. I used center point focus under the spot metering... BBF=>half shutter=>recompose=>shoot. It is awkward and I'd really like to find a better, yet still keep my triple-back-button setup.
The metering is very heavily weighted towards the selected focus point, but proper AF-point linked spot metering is reserved for 1-series. Even the R3 doesn't have it, the expectation is that the much rumoured R1 will get it.