After reading manuals, I am still confused. Does this mean that:
1)user can use only four different effect presets on MX?
2)any of four different effect presets can also be applyed on up to four different parts or more?
3) does dual effects mean that effects can be spread to eight parts?
Thanks for help

With MX series, you can apply simultaneously up to 4 sinlge insert effects (of any available type/preset), one for each of the 4 parts of a performance. In MOXF for example, you can use up to 8 dual insert effects (that is 2 insert effects per part, 8 parts max).