Excellent work Henry.
I thought you were perhaps a bit optimistic about the total cutting time of 1 minute because that is an extremely long toolpath.
After trying to measure the toolpath I decided it would be easier to cut one myself. This is 200mm diameter and took 3 minutes 59 seconds according to the Mach3 elapsed time counter but the mass of my machine is a lot greater than yours and even with a feedrate of 2000 mm/min my acceleration / deceleration times slow it down considerably.
They say that imitation is the most sincere form of flattery and perhaps they are right. Once again nice job.