"Natural instrument noises including:

    - Variable action key release noise (varies with note duration and key release velocity if present)
    - Damper noise at key release (mainly for bass notes)"

The only thing missing for the harp is not 2 kinds of release noises but attack noises to emulate the variable angles of plucking the strings of the harp. That would contribute to the realism of the instrument.

Since the harp string is not triggered by a hammer at an invariable angle like piano instruments, its sound, although convincingly modeled, is handicapped by the absence of the initial pluck sound of the string.

Pianoteq needs a round robin system for its harps.

In its current state, we could say that the harp is triggered by a mallet system, and is more of a hybrid with the piano. It loses much of its delicate sound just because of a slight detail, though the main resonance and acoustic properties is excellently emulated.