I've been playing a bit more with Voicing Mode=Key and find it quite pleasing. If you want to try it with an existing library file, it's quite easy. Here's a snippet from a song I was working on earlier using a SlowBolero Groove:
Tempo 105
Keysig Eb
Groove SlowBoleroIntro
AllGrooves Chord Voicing Mode=Key
1 Eb
2 Dm
3 Cm
4 B&7
Repeat
Groove SlowBolero
5 Eb / EbM7
6 Eb6 / Edim7
7 Bb7
8 / z
Groove SlowBoleroPlus
9 Fm / FmM7
10 Fm7 / Bb+
11 Eb
12 /
Notice how the AllGrooves command overrides ALL of the existing Chord Voicing directives in the lib file. They were set to Chord Voicing=Optimal.
The important thing to remember with AllGrooves is that by setting "Groove anything" ALL the grooves from the file containing "anything" is loaded into memory ... and the AllGrooves command is applied to ALL the in-memory grooves.
Hope this helps.