True, but just like economy passengers being pushed towards the fast-track security line by security when no premium passengers are there, it seems like a vast waste of resources otherwise.

To continue the story, there was no 'fast-bag drop' available, or as I am seeing increasingly now, almost every counter is called 'fast-bag drop' and takes just as long. Anyhow, I returned back to the WT/WT+ area and spoke to a BA agent standing around. The conversation went like this:

Me: I'm on BAXXX to LHR and just need to drop off my bag.
Agent: Then sir, you need to get in the line like all these people.
Me: This line is huge, and will take at least 60 minutes for me to get through. I need to be walking towards security in 30 minutes.
Agent: Then we'll pull you out of the line when the time draws near.
Me [slightly cocky, I admit]: Instead of shuffling for 20 minutes, why don't I just stand next to you, until you call people for my flight?
Agent: You can do whatever you want sir.
Me: I'll stand right here then.

Fifteen minutes elapses then she whisks me to the front and drops my bag off.