You are correct, and Investments tab should eventually be mature enough to handle splitting up of capital gains/losses from unrealized exchange differences.
This is because a combination between a capital gains/loss and an opposite unrealized exchange difference can swing either way. So it is essential to be able to split them out in order to tell what is really happening with investments and make informed decisions.
This is the only logical extension to this idea:
And since that has been closed, I am going to place this idea, even it was still premature.