I just got the 8-cup Yama stovetop vacuum brewer, and immediately noted the large amount of water left in the carafe. I typically brew 20 oz at a time so this wasn’t going to work out because that water would dilute my coffee too much. As I had done with my Cory brewer I extended the dip tube with a piece of rubber hose.
This tube I used silicone rubber hose as it’s resistance to high temperatures and is food-safe. I happened to have some 1/2″ ID, 3/4″ OD firm tubing from McMaster Carr (51135K86) which worked well. I had to immerse the tube in boiling water to get it over the tube, but once on it’s a snug fit so no worm clam was needed. I started with more hose than I needed and whittled it down until the carafe was left with a thin layer of water across the entire bottom. As you can see this wound up being about 7mm of tube extension.
Here’s a short video showing the amount of water left: