Do you mean trapping or choking?
Believe it or not, 'choking' is the better one, although only advisable on an underbase/underprint.
( or if someone is really getting on yer nerves )
The whole X4 thing, while relevant to the question, is circumstantial,
and should not be confused with the underlying factors involved when choosing one method,
the other method,
both,
or neither.
If you manually sep each plate, outlines are handy ( either black or white, behind or overlapping ).
For Corel's ( or Illy's ) automated BS...last time I checked it was still set up more for offset printing.
I always sep in a raster program ( didn't always, but for a long time now..pixel data doesn't lie )