Birth Of A Variaton?

IN 500 Master Games Of Chess by Tartakower and du Mont, the Siesta Variation of the Deferred Steinitz Defence to the Ruy Lopez is credited to Capablanca.
The "birth of a variation," according to the authors, occurred in the following game:
Endre Steiner* - Capablanca
Budapest 1928 (known as the Siesta Tournament)
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 f5

So far so simple, but there is a problem - Capablanca had faced the move 5...f5 in his match against Marshall 19 years earlier.
It was game 14, and ended in a draw (Capablanca was leading by seven wins to one in the match, which was promoted as being for the US championship and was to be the first to eight wins).
But that is not all - back in 1892, at the German chess federation's seventh congress master tournament, held in Dresden, von Scheve played the "Siesta Variaton" to draw against Walbrodt.
Of course it is easy to be wise with the benefit of a database, but it is surprising neither a strong player such as Tartakower, nor a leading writer and chess editor such as du Mont, was apparently aware of 5...f5 being played in the Capablanca - Marshall match.
Anyway, putting chess history aside, how should White meet the Siesta (the move 5...f5 is still relevant today, being second in popularity to the more conventional 5...Bd7)?
The game Walbrodt - von Scheve went 6.d3 (reminiscent of a popular line against the Schliemann) Nf6 7.Qe2 Be7 8.Bb3 Na5 9.Bc2 0-0 10.Nbd2 f4!? (½–½, 22 moves).
White reacted more energetically in Capablanca - Marshall: 6.exf5 Bxf5 7.d4 e4 (the same moves were played in E.Steiner - Capablanca, with Tartakower commenting: "It is clear that Black's game will remain powerful if he can maintain this advanced post") 8.Qe2 Be7 9.Nfd2 Nf6 10.h3!? (Stockfish10 and Komodo9 strongly dislike this move, and subsequent games featured 10.0-0 or 10.f3) d5 (½–½, 31 moves).
The Siesta still occasionally appears at high levels, with the most recent game involving two 2400+ players in ChessBase's 2019 Mega database being from last year's French club championship. Yuri Solodovnichenko (2531) - Deimante Cronette (2461) continued 6.exf5 Bxf5 7.0-0 Bd3 8.Re1 Be7 9.Qb3 Rb8!? (9...b5 10.Qd5 Qd7 11.Qxd3 bxa4 is considered the main line, but looks pleasant for White) 10.Qd5 Bf5 11.d4!? (the uncredited annotator in Mega19 points out that 11.Bb3 was played in a 2015 ICCF correspondence game, and is preferred by the engines) Nf6! (this double-pawn sac seems to be Black's only decent move) 12.Bxc6+ bxc6 13.Qc6+ Bd7 14.Qxa6 e4 (for his two pawns, Black has the bishop-pair and kingside attacking chances) 15.Ng5 Rb6 16.Qe2 d5 17.Bf4? (the bishop becomes a target here - the engines reckon 17.c4 or 17.a4 keeps the game in balance) 17...0-0 18.a4 Ne8!? (a retreat, but it lets a more powerful piece - the queen's rook - join the kingside attack) 19.a5 Rg6 20.Nxe4 Rxf4 21.Ng3 Re6 22.Qd2 Rff6 23.Re5 Bd6 24.Rxe6 Rxe6 25.a6 Qe7 26.f3? (White spent almost eight minutes over this move, which leads to a quick loss, but he was in big trouble anyway) Bxg3 27.hxg3 Re2 28.Qd3 Re1+ 29.Kf2 Bb5! 0-1
*The attribution "A. Steiner" in the book seems to be a mistake.