I can't do it either but I don't think you need it anyway. As an ender neither. Isn't the optimal combo B123, 33, 123, BF2 amp?Is there any secret to getting Sonya's f4(1+3)2222 to come out consistently? The 2222 never wants to come out regardless of speed or timing.
[Edit] Fuck this string. You can just end with b1~bf2 for a reliable ender that deals only 1% less damage or dash-33~bf2 for around 31%. SO, like, b123-dash-33-dash-33~bf2. That same kombo ended with 33~KB deals 47% meterless.
Also what combo are you doing for 47% meterless?