Epson 3880 VLM ink consumption

Hello everyone.
I recently outfitted an Epson 3880 with Piezography Pro inks.
I am finding that the VLM cartridge (Warm Tone Medium Grey) is being consumed far more than any other cart. It is empty while the others are 2/3rds full. All I have been printing is Clay Harmon’s B&W Torture test. The prints have been perfect.
Does this seem normal?
Thank you.

It’s normal


Thank you, Walker. I thought there might be something wrong with either the cartridge or the printer.

I’m curious about the ‘Clay Harmon’s B&W Torture test’. I looked at his site and can’t find a reference to it. Any leads to follow?

Sure, here is the web page:

Just scroll down a bit.