In October 2017, after the 2017 WC, which just took place in Montreal, Canada, a social media video showed Shirai's successful execution on floor exercise the triple Y-turn, now officially named the Mustafina on floor, after Russian gymnast Aliya Mustafina with D-score of E (0.5) in the 2017–2021 CoP for WAG. Shirai was then subsequently compared completing additional skills on more WAG apparatuses such as executing a partial routine on uneven bars, also at debatably higher levels. In December 2018, another clip was shared/compared of Shirai quite clearly better executing countrywoman Mai Murakami's entire competitive floor routine to music, particularly for the most difficult skills—some not even assessed in MAG—like the Gomez on floor exercise, or quadruple turn with free leg below horizontal, by Elena Gómez of Spain, who originated this skill at the 2002 WC, it is another spin that the FIG assigned the same difficulty value of E (0.5) in WAG's 2017–2021 CoP too. With Shirai's knowledge, there has been another compilation video then shared by his fans showing Shirai in training skills, which could potentially become any future arsenal of possible advanced original skills in competition on floor and vault, including a "RO–BH–4½ twist punch ½ or full" on floor, and "½ on–3½ off" on vault too.