Re: too many times
"adds a good 20 - 30 minutes to the install time"
That works is, on buying the new kit, you are doing your own install. But if you are buying the kit INCLUDING install-to-desk, the installers are usually being paid a small, fixed price and have to install a certain number per hour. Niceties will be skipped simply because there isn't time because the buyer didn't pay enough to have to job talk even 10 minutes longer per unit.
On the other hand, I've been in schools in the past where the screen had both VGA and DMI leads installed because, well, that's what came in the box. I've seen others where, a year down the line, the plastic protective film was still on the screen (both self-installs, not done by suppliers)