Can’t help you with smoothie board settings, you have a ton of setting to set speed, acceleration, jerk….Usually no where near 3D printer settings so you can’t really go by that. Make sure you are not using arcs in your gcode for now, that seems to screw up most holes.
You need to do some research on feeds and speeds. You can’t just go slower, chip load is a factor. I am assuming you are just burning your way through the material and not actually cutting it at that speed. 1mm bit is too small, its requirements are very precise.
You are new to cnc and you have the two worst materials to learn on, ply and acrylic. If you can’t find the high density foam at your hardware store get the softest wood you can buy, usually pine.
Have a look at my videos and try to get your setting close too mine, start there.
If you can move your spindle up. Mount it so the bottom of the collet is as close to the bottom of the z tubes as possible, and move your material up even higher.