To complete the speech, it may be useful to remember that if Hauptwerk does not have an allocation algorithm that suits you then within certain limits you can create one yourself (and outside Hauptwerk).
If it may be useful to extend the concept of "Tone Matching Mode 1 & 2" using less than 12 speakers you may consider a hypothetical "Tone Matching Mode 3".
All of Hauptwerk allocation algorithms assume that each note is statically allocated in A channel. This is a correct assumption but in some cases the intermodulation distortions that occur when using intervals other than octave/unison are quite annoying, especially if you use saturation plugins (which exalt the distortions).
If you are using 6 speakers (or less than 12) you can dynamically manage 12 chromatic notes allocations to avoid overlapping intervals different from unison/octave on the same speaker. This means that a same note may appear, at different times and at different contexts, in a different speaker in order to avoid intermodulation distortions. This works well until there are up to 6 different chromatic notes at once. Obviously the ways of implementation can vary, but the underlying concept is always the same.
Tone Matching Mode 3 does not exist in Hauptwerk. To simulate it, you have to use 12 virtual chromatic channels with Hauptwerk and manage these 12 channels within a VST/AU plugin in a DAW. In practice, you can create a mixing rule from 12 notes (=chromatic scale) to less than 12 available speakers.
It's not a simple thing but Ardour DAW can help you do this with a Lua DSP script.
http://manual.ardour.org/lua-scripting/I wrote a script that does this and works well at zero latency.
Later I will publish an easily manageable version with a friendly user configuration interface.