Just a quick remix with a 0.3mm slice of the top mirrored on the bottom so it prints the design on the bottom without supports. The original size is approximately the same diameter as a Canadian $2 coin but as thick as a 1oz coin, so I made a 40mm version that is about the same diameter and thickness.
0.2mm layers x 0.4mm nozzle
I found for 0.2mm layers I had to set 0.1mm to be cut off the bottom so it only had 1 layer of the design on the bottom and then 3 layers on the top instead of 2. If your first layer is 0.3mm, no adjustment is needed.