True. I'm inclined to think it would be closer than 'do whatever you want in order to end up with an Xoz drink' though!
By comparison, the same 18g brewed using a pour over method should yield an 8oz cup of coffee with … likely around 170mg of caffeine.
Check out this James Hoffmann video specifically on this topic: https://youtube.com/watch?v=etnMr8oUSDo