For the Greek text of the New Testament in the Lexham English Bible (LEB) -- the SBLGT by Michael W. Holmes was used. I think it would be interesting if I quote what Stanley E. Porter, who authored How We Got The New Testament has to say:
"In many ways similar to the Nestle project, Holmes's edition uses Westcott and Hort's edition as the base
and then compares it with those of Tregelles, the NIV, and the Byzantine text of Robinson and Pierpont. His procedure is generally to accept their reading when they all agree (although this is not always the case) and
then to determine the correct reading where they do not all agree. In a few cases he adopts a reading not found in any of the editions. It appears that Holmes has simply used these four editions to ensure the secure 90 percent or more of the established text, and then he has gone on to make his own decision for the remaining portion ---except, apparently, where he thinks he knows better, even than the undisputed tradition. This may not be the best way forward in textual criticism of the Greek New Testament." (p.51)"
"In many ways similar to the Nestle project, Holmes's edition uses Westcott and Hort's edition as the base
and then compares it with those of Tregelles, the NIV, and the Byzantine text of Robinson and Pierpont. His procedure is generally to accept their reading when they all agree (although this is not always the case) and
then to determine the correct reading where they do not all agree. In a few cases he adopts a reading not found in any of the editions. It appears that Holmes has simply used these four editions to ensure the secure 90 percent or more of the established text, and then he has gone on to make his own decision for the remaining portion ---except, apparently, where he thinks he knows better, even than the undisputed tradition. This may not be the best way forward in textual criticism of the Greek New Testament." (p.51)"