The GF splits operations by color (not layer), so you will want to make your cut-line a unique color in the design.
Not sure if you mean printing the labels on a different machine and then cutting them on the GF, or printing with the GF and then cutting with the GF…
From my limited experience, I think that if you are bringing in prints made on a different machine and lining them up visually to cut, you would probably still be served well by making normal trim and bleed zones. If you are printing with the GF and then cutting all in one operation, you can skip the trim and bleed.
have you seen the community tutorials matrix here?