I bought my pro hunter and they had just come out with the swing hammer and still had the hex wrench to remove the breech plug / 90 degree turn .. is the newer speed breech knurled knob compatable with all speed breech style plugs?

I would say not but, not for certain. Usually the hex heads sit back inside the breach, where mine sits between the barrel and the face of the frame. In other words you can see my BP (the knurled part) behind the end of the barrel and the frame. Most others I have seen set inside the breach area and can not be seen unless the barrel is broke open.

I doubt it will work, you can always call T/C and ask.