I have replaced the touchbar, the top case, tested a new Display Assembly, and the worst one of all I even replaced the logic board on one with the update error. Still got the update error. All software related to when you erase the onboard storage via disk utility and it erases the “hidden” touchbar OS
So battling this issue on 10-20 machines. 15in 2016-17 Pro’s and We have tried everything excluding the LCD to fix the issue. One unit has a brand new Logic Board and Top Case and still got the critical update error. Have a whole lot of paperweights over here..
Save yourself the possibility of lines in the LCD, just clean up any excess glass and apply the new bezel over the existing. There is glass under the bezel and cables that even the slightest strain will cause lines. If lined up correctly the second bezel is unnoticeable and does not cause clearance issues.