I have seen their videos, and I also believe, with very few exceptions (one dude in Brighton), their work looks, less than optimum.
The route I am following is ordering from a company whose business model is to support remote customers. (OneHead). They are willing to as little or as much as you are comfortable with via Skype, Facetime, etc. (no additional costs). I chose to go to their Madrid location for a consult, I think they have a location in London. I will go back for the cut-in, and instruction on self-maintenance.
I know that there are other companies that provide similar service.
As for "plucking the hairline"... do you REALLY want to go through that hassle after spending that much money? They could have easily gone the route of ordering the system with the correct density at the hairline. I start to wonder, when I see the videos, the person gets measured, and then fitted, how many of them are getting something custom, or stock? If you are going to go down this path and spend some serious cash, I would guess you would want something that looks as natural as possible?
Good luck!
P.S. Check out Curtis: He does everything DIY, after getting his first systems from a salon.
https://www.myhairexperience.com