Q: Can the Insta-DE, Insta-DE 2, Insta-DE 2a, Insta-DE 2af Screen be cut to a custom size to fit a particular set of dimensions? If it is possible, do you recommend a particular tool to get the cut right?

Yes, the Insta-DE, DE 2, DE 2a, and DE 2af can be cut to size.  It is strongly recommended to use a long ruler and a sharp blade such as an exact/utility knife or a precision cutter tool to make a smooth precise cut. Make sure the blade is new.