Thanks for the great suggestions, guys, but in the month between question and answers, I broke down and purchased an MSR Titan Kettle at 850 ml. It has a pretty square form, viewed from the side, should be efficient.
Although the Evernew 600 was tempting, I was afraid of boil-over, as I sometimes need 2.5 cups (590 ml) of hot water for a breakfast.
I'm getting used to the Titan Kettle -- you'd think it would be an automatic upgrade over the Grease Pot, but it has a learning curve of its own. The deep (vertical) handles make it tricky to design windscreens and cozys. And the lid, as has been mentioned many times, is tight, meaning you have to risk your hands on the hot handles to get the leverage to pry the lid open. And there are no graduations inside, a major drawback.
It is however the perfect size for my solo use, and it has a reasonably wide bottom, useable for either sideburner or center.
This is my first Ti utensil, and although it's nice, I'm not certain it's an upgrade over aluminum. I think my 4.5 cup grease pot with lifter weighed the same as the 3.6 cup Titan Kettle.
Evernew needs to fill the space between 600 and 900 with a square-form 750 pot. There is the 750 pasta pot but it is tall and thin.