As it stands, Inventor requires the user to "Add to Accumulate" the areas of individually-selected surfaces, one surface at a time. This can be very time consuming on a complex part AND... Inventor does not display which surfaces have been selected for accumulation, so the possibility of double selecting a surface is very real.
It would be nice if Inventor allowed for multiple surfaces to be selected (changing color to show which ones have been selected) before clicking the "Add to Accumulate" function.