Back to the original topic --
I use two 1400's. I leave the connectors installed in one. As you might imagine, connected together is for ripping plywood or long trim pieces from hardwood. Separated, I use the one without the connectors for cutting out panels.
For the initial breakdown of plywood I have two inexpensive roller stands that I set to about two inches above the tailgate height of my pickup and lay a 2 x 4 across the edge of the tailgate. I pull out a sheet so one end is resting on the roller stands and the other is on the 2 x 4. I set my guide rail in place, make sure the gap between the two roller stands coincides with the cut I am about to make and make the cut.
Prior to breaking down the sheets, an accurate cut list should be made, detailed with grain orientation and anything else that will assist in making each cut a final cut. Then I make accurate rail positioning sticks out of scrap for most of the needed cuts.
Doing it this way makes it possible to cut and assemble much, if not all, of the cabinetry on site, quickly and accurately. With the Festool dust collection hooked up there is more mess drilling the holes for the screws to assemble the cabinets than cutting the panels.
So rather than deal with a 3000 cm rail, I vote for two 1400's.