Just curious if you considered an iPad Pro as second screen. I hear that certain software like Duet Display does a pretty good job and let you use it's drawing features with your Mac. No experience with it, but am thinking about getting Duet Display Pro myself.
If they were going for a no holds barred top of the line model they could go OLED which isn't several discrete layers bonded into one but effectively a single flexible sheet of plastic with small diodes 3d printed onto it - that would certainly be thinner and lighter!Since 2010, have the LCD panels been improved to the point that for a 17" screen, the weight has been reduced by at least 30%?