The end of the world does not depends on it, so I guess is not so important. :D

Would be a nice thing to have though, as many players seem to use the estates improved skill. As for me, my TEW3 map uses it intensively and I wanted to make a script which shows the real income but then I saw is special screen, need UN:C or else. I can work around, store gold when end turn clicked, then compare with next day, then display in some box. But is not real time, if any changes occur during the turn, it won't display until next turn.