I always have trouble with it melting, but I probably wasn't doing something right. I love machining it though. :rainfro:
I use it for handles mostly, "one-offs", but if I did production, I would want some kind of cooling. Compressed air might be all you need. I'm pretty sure I used HSS, I'll bet the diamond cuts cooler. Maybe a slight melt contributes to the fine finish you saw.
Play around and let us know what works out!