PS: Here you can see a spindle driven to its limits. It’s a Jianken 2.5 kW but as Jianken writes the so-called apparent power on their nameplates, the mechanical power should be someting around 1.8 kW. It is rated 6.6 A but you can see in the video that it is driven to 10 A (on longer duration the VFD would trip then). Also you can see a link to milling black locust with a 8 mm roughing bit with a 6.6 kW spindle.
PS2: Pine is a soft wood, but its knotholes and the dark part of growth rings is denser and harder than a hardwood. That’s why softwood timber with knotholes is only present in the furniture industry since the advent of HSS. Conifer knotholes made hardened carbon steel (as used in handplanes and chisels until the 1950s) dull or break it.