I believe that I did all three of those presets, so I guess I'm the defendant in this case.
As a start, I try to loosely consider keyboard controllers that don't feature mechanical Channel AT, but have the ability to assign channel aftertouch to a knob or wheel. The main objective, though, is to use a control message that can be used in combination with another (usually Mod Wheel - CC#1, to be democratic). That combo will still leave one hand free to play the keys, and two hands if the Mod wheel can remain 'parked'.
... the sound ends too soon (due to their nature - bass, keys, etc) before one can notice any changes, so the use of Aftertouch in this way makes no sense to me. A DIFFERENT controller should be used here (instead of the Aftertouch).
I disagree, and here's why: The channel aftertouch value generated is the highest additional pressure across *all* keys. So, if you hit a note, press to generate aftertouch, and then
hit the next note, the channel aftertouch value is still active. If you are strictly playing staccato, you won't notice much difference.
And *that* is something that can be used to your advantage: as a performance technique.
The effect on
Simple Filter Bass is subtle detuning, vibrato rate & depth increase, and stereo widening. It becomes more distinctive when Channel AT is held on at least one note, more notes follow, and the Mod Wheel is engaged. Vibrato depth is enhanced by added detuning. With
Modal Quick Strummer, the panning tricks get exaggerated to the extreme. I was looking for subtle animation under fingertip control here.
But the most obvious example is found in
Combination Lock. Hold Channel Aftertouch on a single key, and play a flurry of additional notes. The sharp attack notes turn into 'reverse-tape' long feedback notes that spread out further toward panned extremes. The deep multi-oscillator detuning with the Mod Wheel thickens up the entire soundfield. The idea was to switch from relatively centered staccato to notes flying in from everywhere.
That's the "
Combination" part. And channel aftertouch is the "
Lock".
Edit: I should add that the Smooth values in the Modulation Matrix are no accident. By shifting in different maximum smoothing times with channel aftertouch, you're assured that there are no sharp transitions between 'effects'. And the values of those effects present themselves in varying proportions; depending on the current pressure applied. More performance techniques.