For those interested, test I wanted to do is complete.
Same quantity of wood versus pine cones... both using the same starting method (although I need not have bothered with the pine cones, they went up in seconds) and both using exactly 800ml of water with a starting temperature of 15.8 degrees Celsius.
Wood took 5 minutes and 12 seconds to boil the water to 97.2C... maximum temperature at chimney opening was 640C.
Cones took 5 minutes and 49 seconds to boil the water to 98C... maximum temperature at chimney opening was 610C.
Time being largely irrelevant as it turns out, and being the same quantity, space isn't a deciding factor either.
What is a good deciding factor is the way the cones burned... the initial cone lit easily and rapidly lit the others around it. I used 19 cones in total, though they were smallish cones. The wood took a little more coaxing to get going.
Next test, going to see if I can cook using just cones using the hobo stove attachment to the KK... my youngest kids are enjoying collecting them and my eldest thinks I'm nuts for using a digital thermometer to measure what a Kelly Kettle does. I don't care, I'm having fun and its a good excuse to use the kettle in the garden
In fact, I think to test the cones properly, I may just have to sit out there each day for a bit... all for science of course.