I agree 100% with the smart pickup conversion---I have 3 of them---but disagree 100% with pickups that use the sign system. I was burned by a pickup customer a long time ago and since then refuse to acknowledge the "Yes"/"No" or "UPS" signs.
I feel like the same thing applies to using a phone for pickups. It's can be the appropriate level of customer service depending on the business. Even with a Smart Pick Up, a customer might call and say they are just going to deposit the parcel in a UPS Lettterbox.
With the company's new miles obsession over safety and service, I don't really worry about the integrity aspect. However, if you get a corporate concern about how you failed a pickup account and you try to use the "But I talked to them over the phone!" defense, that is not going to fly.