Interesting but no I have not done this officially. I tend to just run a a couple cents sharp as I go up the trebble side of the middle intervals and a couple flat as I adjust into the bass. At each octave I allow a drift, if you will. And at that I have not decided if this is how I want to continue. Do you tune for pure unisons ? I notice in some old tapes of Horowitz that his piano seems to be tuned slightly off pure but yet the harmony is very good. That could be the old recordings just as well.. I'd love to speak with his tuner if he is still around !
Speaking from a vast and deep well of no knowledge about this at all -- I have a very good piano technician who does my tuning for me, thank you! -- you bring up something which I have always wondered about, and never gotten a decent answer to. Maybe this is the time...
In principle, a pure massless and infinitely flexible string will have a definite fundamental frequency. Further, it will also vibrate at exactly twice that frequency (second harmonic)(the octave) and three times the frequency (octave and a pure fifth) and four times and... and so on. But... a piano string is neither massless nor infinitely flexible. So -- is the frequency of the first harmonic (the octave) exactly twice the frequency of the fundamental? Or is it slightly higher? And if isn't exact, should (or does!) one tune the octave to an exact octave, or does one tune the octave to the actual frequency of the second harmonic? Although the differences -- in theory at least -- should be small, wouldn't it make a difference to the brilliance and singing of the piano, particularly with the dampers raised?
This isn't a question of temperament -- that's a whole different subject -- but pure physics and acoustics.
Illumination, please!