Thank you for the good advice, and the clarification on the toolstick from Jim.

Count me as a Luddite Erik.
(As it happens, I live and work in the village - Calverton, Nottinghamshire - where not only was the Stocking Frame invented by the Rev William Lee, but Ludd - the fabled leader of the smashers of the stocking frame also came from... Though, like Robin Hood, it's believed that no actual person called Ludd existed.)

As I said, I like 5v for the increased dynamic range it gives to my ADC inputs. However, I can still supply the sensors with 5v, as their output is ~2.5v. I can set Vref up to 3.3v (Vdd) and, given the 850's 12b resolution, it will be fine. I also note that it's possible to set 0.5 gain, giving an input range of 2xVref, though this is limited to an input of Vdd max.

Still a damned nuisance to have to provide 3v3 as well as 5v.

Cheers, Dave