I've been playing around with K' in training mode for a few hours and I've noticed that there's some viability with the Heat Drive combo extender.
My hypothesis is that you cannot do EX Air Minute spike after Heat drive. I noticed this after about 20 attempts of trying to do EX Air Minute spikes and failing every single one. I used the same timing and same method for a regular Air Minute spike and it did work every time.
So here's a truth: After Heat Drive, you can only do regular Air Minute spike
And another: You cannot HD bypass Air minute spike using the qcb, b method.
Timing: Right after the body hits the floor, your window is open to do it. The body has to hit the floor, don't do it before. If he had that, that'd be pretty broke because he could HD bypass EX/Air Minute spike into combo for free or get a free combo from his super which would REALLY put him over the top.
If someone can do a TKed air minute spike after Heat Drive and make it HD bypass, K' might really be nutty.
After messing with qcb, b shortcut to do air minute spikes, I felt comfortable with it and could do the combo easily. This is very useful because of the viability of carrying someone to the corner and letting loose all if not most of your meter on someone. Even if we have to spend meter and drive instead of going into HD, it's still a lot of damage for mostly stock use and capitalizes on jump-ins that won't do conventional non-meter combos.
Here's what I could come up with as midscreen BnBs depending on meter:
Midscreen (From 1P start position): 1 meter
Hop D, st.C (1), qcf+A, f+D, qcf x2+P, -wait till fall-, qcb,b+K = 382 dmg
2 meter, 1 drive
Hop D, st.C (1), qcf+A, f+D, qcf x2+P, -wait till fall-, qcb,b+K, qcb+BD, dp+A = 431 dmg (DP+C ender)=512
*Note: If you do dp+A, it does less damage, but you have a chance to go for a throw if they tech the soft knockdown which would do more than the DP+C
3 meter, 1 drive
Hop D, st.C (1), qcf+A, f+D, qcf x2+P, -wait till fall-, qcb,b+K, qcb+BD, qcf,hcb+P = 589 dmg
*Note: HKD plus the last hit does 70 dmg unscaled, have to do the super as fast as possible to get it to hit.
4 meter, 1 drive
Hop D, st.C (1), qcf+A, f+D, qcf x2+P, -wait till fall-, qcb,b+K, qcb+BD, d.C, qcf,hcb+AC, -wait till fall-, qcb,b+K = 698 dmg
*Note: Pay attention to see if they even try to tech because that's a free grab!
Take note, these are all midscreen combos and possible whether you screw up your spacing to get a no meter combo or not. The first combo does MORE damage than your regular 1 meter BnB and gives less meter. Something to think about. These work best APPROACHING the corner. At the end of Heat Drive, you've got to end up at the corner to do the rest. Trying out things to see what's plausible afterwards.