I think I have the handle on this.
I anchor multiple work pieces to spoilboard (different thickness). Then establish x,y and z origin on one of them. Go to Run/quick actions/user and save the location. I do the same for each work piece.
I can then end the work session and turn off CNC. I come back later, connect cnc, initialize. then go to run and do the tool change. At this point I am exactly where I was when I turned CNC off.
I find this useful when doing a 3d carve and remove the material where the origin was. Easy to end session, come back next day, different tool and continue.
Also if doing a larger sign with multiple letters on different work pieces. I run ,say 1/4 mill on each work piece by changing origin, then change to next tool and do the same and so on. This way I do one tool change per tool.