Same here. Is there anyone at Apple that can shed some light and provide some kind of direction on this? I mean is this an Xcode issue or something that devs need to address or is this for the 3rd party whose library and frameworks are causing this issue to fix?

For people that come here looking for an answer... after invoking the build using the Product > Perform Action > Build with Timing Summary, once the build is done, select the build in the Report Navigator (⌘9) and then selecting Editor > Open Timeline. This will open the timing summary along side the build log. Note that as far as I know, the flag ShowBuildOperationDuration is only used for showing the duration of the build in the toolbar; it is not required to be set for the build timing summary.