Steve D wrote:
> [variation in tie formatting]
> That is just my opinion. ;-) I don't understand, however, why LilyPond's
> tie placement behavior varies between the pairs of identical chords
> (pitch-wise) sited above.
The height of a tie depends on its length. Shorter ties are smaller in Y
direction, meaning that they more easily fit in spaces. Without studying
the code, I guess that for the half-note case, the tips of the ties
would be too high relative to the note head if it was in the same space,
so it is moved one space outward.