I disagree about the Super Kick and the “green projectile”. The best cancel option I found for both of them is off b1. The fastest B1xxSuper Kick cancel I did was -7 on block, the fastest b1xxScreaming Soul cancel is -3 on block. But you have to look at several other factors in terms of pressure. The projectile itself doesn’t represent any danger up close, even if you take Amplified version into account. And you have to commit to it off b1. And b1 by itself is -2 on block, so it is a better stagger by itself.
With b1xxSuper Kick you get a hitconfirmable launcher. The kick itself is -9 with pushback, so it isn’t easy to punish. But there is a gap which you can FB. I wasn’t able to interrupt it even with a 6 frame normal, but in theory there supposed to be an 8 frame gap (even if it is indeed so, 7 frame moves will trade granting you a combo). So if your opponent’s best option here is FB, canceling into -7 is good enough to stay safe on block confirm, and even stagger. On hit you get a combo so it is much more rewarding. And Super Kick is a great combo extender over all, because it gives you corner combos, and doesn’t conflict with db1 or bf1 flaming skull (which is a much better projectile in neutral than the screaming soul). It connects from all starters just like Ground Eruption (unlike Corpse drop), and doesn’t replace the default db1.