That's some pretty nice burly spalted maple there!
Side note: for similar cuts for turning, I made myself a small sled that runs in the miter slot. It made getting consistent cuts a lot easier/safer and I could shave the last bits off a bit easier. I don't have an outside index (fence) but just eyeball from the cut line. I added some "swing into place" arms made from flat iron with short spikes welded on the end to hold things in place and a front "stop" with a couple short spikes on it so the piece is pretty well locked in place while I slide it into the blade.