Refined methods for unloading one card of a double after executing a Double Lift lift are quite old. One appeared in an anonymous notebook c. 1800. The author attributed the technique to Herman Boaz. Will Houstoun transcribed the book and released it as The Notebook, 2009; see p. 27. There, the lower card of a double is unloaded onto the deck, with the double held between a finger and thumb, as if for a Top Change.
The concept caught on in the twentieth century, with several modern approaches hitting the scene. R. Shrimplin described a simple drop-off from end grip, dubbing it the “E-Z Top Change” in The Sphinx, Vol. 19 No. 2, Apr. 1920, p. 35. Chas Eastman described Tommy Tucker's handling in Expert Manipulative Magic, 1933, p. 13. Stanley Collins included his method as a conclusion to his “Esscee Double-Lift” in A Conjuring Melange, 1947, p. 97. A pivoting motion was introduced to the idea by E. Brian MacCarthy as a Top Change alternative in Sleights Supreme, 1948, p. 32. Max Katz also developed the pivot dynamic, but swiveled the top card in the opposite direction to that used by MacCarthy. Katz described this in M-U-M, Vol. 47 No. 3, Aug. 1957, p. 100. This is similar to the commonly cited Dai Vernon replacement that was published four years later in Further Inner Secrets of Card Magic, 1961, p. 70.
A popular related technique, employing a Double Turnover instead of a Double Lift, is attributed to Frederick Braue, Juan Tamariz and Gordon Bruce. Braue never published his handling, but recorded it in his notebooks; see The Fred Braue Notebooks, Volume 3, 1985, p. 25. Tamariz contributed his handling, called “The Tamariz Turnover” to Pabular, Vol. 7 No. 1, Jan. 1982, p. 970. Bruce's version appeared in Pabular, Vol. 7 No. 4, May 1982, p. 1024. These three techniques vary slightly, but are based on the same central handling.