I made this same request many moons ago. I can understand that it might require a lot of resources but it might be something to at least look into to know for sure. I find myself physically rotating my 770 just so I know if I need to make a right or left hand turn. Otherwise when you are heading south your mind sees a left hand turn when in reality you need to make a right hand turn. Reading the directional wording is not always an option and flite isn't always easy to hear plus I've had mixed success in using flite.

A simpler option might be just to have an optional flashing or solid arrow right under the direction balloon window that points in the turn direction when you come to waypoint. Might even color code the arrow that starts out as yellow but turns green as you approach your turn. Hard to know if this would be an option without actually trying it out and might be a problem when you have to make a lot of turns in short order. In any case, I attached a sample image of what I'm looking for.