No, they can't.

It's not usually the equipment but it's sometimes the case that differently trained staff operate the gate from check-in. So the person on the gate simply doesn't know what to do.

Smaller airports such as SVG aren't a problem as you highlight, since it is invariably the same staff. So you may have 2 people on check-in, then at one hour before departure when the queue has typically gone, one person works their way over to the gate, followed by the other one after check-in has closed at T-45 minutes. But in larger airports you sometimes get the check-in staff fixed in place for the whole shift and another team of staff at the gate.