It could get ugly indeed.
For the most part, in my limited experience, most moves are done in an absolute mode. The incremental mode is used mostly in subroutines (not sure if thats what they are called)
where you are machining multiple identical parts out of one piece, the main program takes you to a start point or offset and then you go into a subroutine that uses the incremetal mode and machines out the part, then returns you to the main program in the absolute mode moves you to the next point and loops back to the subroutine to do it all over again.