For those not familiar with seeds, it's a number that creates a different kind of randomness (but always the same for the same seed), so different notes would be affected different amounts -  with everything scaled by the detune factor.  If you don't like a particular random spread, a different seed number will produce a completely different one. 

(you could also just have a 'randomize' button, but having an editable seed allows you to go back to a previous spread & remember your favourites).

+1

That would be a nice extra touch, without impinging on any future PTQ Pro, in which the unison width might be set explicitly for each note.

It's moot whether the "width" should be truly random from null to a specified maximum detuning, or whether it should follow some normal statistical distribution. I would guess real piano follow neither "rule". But I would also guess that Modartt know enough about pianos to implement this in a cool (realistic) way.

My impression is that piano tuners do follow a set of rules in detuning the unisons, but at the same time, it would be good to be able to create an older piano with some unisons that have gone out of tune in unplanned ways. So the interface might let the user do both: There could be a list of standard unison detunings, and a way to move past that to detune each string under a given hammer in incremenets.

That would be a nice extra touch, without impinging on any future PTQ Pro, in which the unison width might be set explicitly for each note.

It's moot whether the "width" should be truly random from null to a specified maximum detuning, or whether it should follow some normal statistical distribution. I would guess real piano follow neither "rule". But I would also guess that Modartt know enough about pianos to implement this in a cool (realistic) way.

Now, let's have it Pianoteq !  ;-)