I skipped steps 13-19. As long as the display is supported and you get the double sticky tape out on step 20, this is a nice time saver and less chance to do damage during re-assembly. Of course if you have problems with the double stick tape, then removing the display is probably a good idea. It’s a risk either way. The main reason for replacing this is slow sluggish performance. I would be texting a msg and the phone could not keep up with me typing. I used Geekbench to run before & after numbers and here’s what I got:

Single Core before 1064 after 1554

Multi Core before 1811 after 2679

The after numbers were typical of other iPhone 6 results. The sluggishness of the phone is gone and it’s back to its regular performance.

Good luck and take your time with any repair!