You press the 2nd "3" after the first connects . Don't just press them quickly. You don't have enough time to delay it, but still, there's a delay and you can use that to CH to surprise opponents and get free combos.
Sure thing. After landing the heat smash, you press: d+1,3 , b+2,3,4 , F (hold then release for DSS) 3 , 2,2,1+2 Here's the console inputs if you don't want the legacy one If you're on Xbox : Heat Smash, ↓+X, A , ←+Y, A, B, →(hold then release), A, Y, Y, X+Y If you're on PS5 : Heat Smash ↓+▢, ✕, ←+△, ✕, ◯, →(hold then release), ✕, △, △, ▢+△