Unlike in Eevee or Cycles the Armory renderer has a bottleneck where in order to see the results of your material you have to recompile the entire game when you just wanna see a slight modification to a material. If you want to view your render from a different angle you have to exit the game and move move the camera manual unlike in eevee or cycles where it can be moved in viewport. Will we ever get it where we can modify materials and instantly see the results with ease?
It may be possible once 2.8 is fully released and Armory can take full advantage of the play in window mode. However, since armory need to convert the cycles/eevee materials to it’s own game engine materials it may never be completely instantaneous and completely accurate at the same time.