To answer my own question, it seems to. I put the wheels on the stand, and gave each spoke a quarter turn, I gave one spoke on each wheel about an eighth extra, that was all they were off true, about 1mm.

I think I've got room for,, another eighth, or maybe a quarter. Not that certain of my judgement.
I'm going to hold off putting on any more tension 'till I get a meter.

There is a definite improvement in ride, sharp seams and the like don't "thud" through the frame any more. You still know you've gone over it, but it feels a lot less, "dead" is the description that comes to mind. The whole bike seems a bit springier.

The wheels in question are from a LBS, supposed to have been hand finished and destressed, they've done about 1500-2000 km from new.