So the advantage of the 4 parts rather than to sacrifice the 16 different patterns having only 1 pattern per part as default, it is to have the possibility to change that slot sample(without altering the trigs configuration?) and the freedom to assign or change the effects of that track? I am trying to solve this.

Also, when You assign a different slot per TRIG in the same track by pressing FUNC + moving LEVEL knob, can you like have the option to edit each “slot per trig” in AED edit page?