The way you've set it up would indeed be frame perfect. I think I've seen something to suggest that frame perfect unblockables are blockable as a player but the training dummy will let them hit. From memory I think it's just the game processing it differently when it has to factor in that the player is holding 4 or 1 and not just a bot blocking perfectly.
To keep this combo-thread-y
in the corner, doing 623C then 2]D[ when they're at the peak of the "launch", waiting for them to hit the ground and then 3C will cross under an emergency tech and you get a quick crossup that's less obvious than Carl shouting "VIVACE!".
From there you can do the following:
j.2C ~Allecan, 4214C]D[, j.2C ~Allecan, 5C, 4]D[, j.C, 7dj, delay, j.2C, j.214C, 623]D[, 5C, j.B, 6]D[, j.C, j.2C, j.B, dj.B, 8]D[, j.C
This alone does about 5.2k damage and builds around 60 heat. You can then 214214]D[, 3C 632146C for just below 7k.
Managing to move Ada forward at any point at the start makes this much easier as 4D and 623D only just reach