Hey Fred,
it is not a solution to screw or clamp the wood so that the warping disappears, because if you loosen the workpiece, then it would warp back.
The fact that wood warps after being cut into boards has been a concern of woodworkers for thousands of years and there are proven solutions for this problem. When it comes to glueing together larger areas of wood that you want to remain flat later, even when the wood is exposed to changing humidity levels, you have to maintain a certain alignment of the individual wood strips before glueing. This is shown here:
Compensating warping of wood. Above: wrong. Bottom: correct.
– Image source: Spannagel, Fritz: Der Möbelbau. Otto Maier Verlag, Ravensburg, 1954.
Reprint: Th. Schäfer im Vincentz Verlag, Hannover, ISBN 3-87870-666-9
This is also often mentioned in woodworking videos, e.g. in this video or in this video.
Still, most woodworkers will say before you clamp a piece of lumber into a CNC, it should be dressed. Lumber, after all, is often not only warped, but can be twisted as well. The dressing is done with a jointer (called planer in the UK) or a combined jointer/thickness planer like the Felder Hammer A3. At least that’s how it’s done nowadays. In the early days, trueing was done with a jointer plane or trying plane (shown here), which is of course still a possibility, especially if the warping is not that extreme, but to use it you also need a proper planing workbench to hold the workpiece while planing. A Workmate may wander away while planing.
You can of course leave the warping in, but then some clamping methods might not be suitable. Clamping from the sides with eccentric lever clamps can of course increase the warping and with the tape and glue method you may not have enough contact surface.