Raise it or waive it
“Any bases for asserting error, whether factual or legal, that are not raised in the principal brief are waived.” Ex parte Borden, 93 USPQ2d 1473, 1474 (BPAI 2010) (informative). See also Optivus Tech., Inc. v. Ion Beam Appl’ns. S.A., 469 F.3d 978, 989 (Fed. Cir. 2006) (“[A]n issue not raised by an appellant in its opening brief . . . is waived.”) (citations and quotation marks omitted).