Well, another 250 miles on the car and what a difference small changes can make.
I am used to feeling the difference between 20' toe out and 10' toe in, but didn't expect to feel it so strongly on the road. The centering of the steering wheel (which means centering of the rack) has resulted in the adjustable power steering working properly, and feedback is more direct. Handling is much more similar to the 2.0 petrol as well, with better ability to carry speed round corners and the transition from a FWD bias to RWD under power more evident.
Immediately, whether due to the wheel alignment (reduction in scrub), non distorted discs causing some pad dragging, or simply she's getting used to more frequent driving cleaning the system/combustion chambers out, today's journey had me up at 43mpg, rather than the 37-38 for the same journey last week.
That's more in line with prior expectations, happier than yesterday
The trip computer can't do maths though. Last week a full tank was apparently good enough for 360 miles, and it stayed like that until less than 3/4 of a tank was remaining. This week it showed 480 miles, when the reality last week for a tankful was more like 580, this week 660