Very nicely done, Paul. That mill is really helping you turn out nice work
Do you have much experience soldering?
Have you considered adding vias to the board?
Is it truely necessary to use SO MUCH copper? What other options would there be for so much current and heat handling? I'm just thinking from a mass-production economics p.o.v.
There is no question, you'll want to use that thermal paste for longevity/safety.
Looking forward to seeing it in action