I would like to have more control over which ink traps into which ink, rather than to have PowerTrapper trap based on 'lightness'?
Answer
The default option in the trap task is to trap according to lightness. If you would like to have complete control over how the trapper decides which colors to trap into which colors, try using the Use Separation Order option.
The trap task will then refer to your Ink Manager ink list to determine how the traps are set up. It will spread the top colors down the list into the lower colors. You could also use the Reverse Separation Order to spread the bottom colors up through the ink list. Any inks set to Varnish or Technical will still not be trapped.
In the Ink Manager, you can click and drag the inks into the desired order for trapping.