Ben have you tried putting on the old pads (if you've still got them) to see if the issue is there?
I still have them but don't think it's the cause of that much travel. I think there is still air in the ABS. The pedal firms up with the engine off, still move a bit too much for my liking. But as soon as the engine is on the travel is just ridiculous.
Have dropps Sam's dad's friend who helped last time a text, been a specialist for 20 years so hopefully he can sort it.