I have not tried it on each and every voice, but I imagine the same rules apply as would apply in other instrument engines... the Attack and Release apply an Offset to the stored setting. The limit is determined by the data it is applied to... if the amplitude envelope can be offset in the direction selected it will... programmers have an option of starting the Amplitude so that at KeyOn it rises from 0 to Attack Level, but they also have an option of starting the Amplitude at a value other than 0. If this is selected slower Attack Time would not be possible because KeyOn is immediately at Level. You don’t get to see that portion of the Preset data, so the behavior is what it is... think of the Attack and Release Knobs as offsets to the pre-determined Instrument Envelopes.

On the opposite end of the envelope, on a sound that is purely percussive in nature, the Release Time may have no effect because there is no loop point segment to fade-out on... the sound simply naturally is over.

Working with stored Live Set entries:
Remember to turn the knob to activate it... in a situation where an Offset is stored in a Live Set, for example, you must turn the knob past the stored Offset... this is called “hooking the value” in order for the knob to become “live”. As you turn a knob the screen will display the current value, not until you pass the stored value will the values begin to change.

Appreciate the response Bad Mister. I'm trying to edit a piano voice in the SUB section and would like a slow attack effect to use on a piano voice in advanced mode.
The attack parameter is not affecting this voice... is there explanation for this?