Yes could have been a lot faster. My firmware is old Marlin_20_32 from early July. I only modified the steps/mm and some stuff for the Full Graphics LCD. I had to disable the awful screeching beep and fix the rotary encoder setings. I don’t think I ever touched the acceleration but I’m not 100% sure.
I set the feed rates pretty slowly to 450 mm/min without doing any experimentation. The 2D contour took 22min, the 3D adaptive clearing/roughing took 1h50m, and the 3D parallel finish took 2h44m. Obviously way too slow. I know I can cut the roughing way down, perhaps by 4x or more with proper settings. I need to do some experiments with the feed rate on different materials. Probably should look at your new acceleration settings along with this. I do like the surface of the pine with the 0.25mm finish stepover but should play with other values.