For beaming away, DemchoH might make sense for describing what people in the room who are watching someone beam away are seeing. That is, it's a way of describing what beaming looks like to those not beaming. But, of course, when beaming happens, the person who beams away doesn't stay there and become invisible. They're gone! Once the person is gone, you might use ngab. loj would be appropriate if you're focusing on the incremental disappearance of the person.