Hi Heli Bee,
I use the same method(s) of cutting large projects. for repetitive work the dowels are king. just lift the work to the next dowel position. for long work with different geometry, a reference point in the cad/cam machine layout has to be established- then create (or move) the design to the next section and soforth...I move the design in the y (in cad) and re-establish the cutpath of that section. you can cut and paste the g-code so you have one file when you are done. A bit tedious but i've managed to cut a 4 ft length out of my A-I design (12x12)
Gadget