Plus, you also have to take into account however they made those shaped pills, fillers were used. If it was pure mdma, it would be white powder, and white crystals. So those must have been chopped powder and crystals, dyed purple with food coloring or something, maybe bonded with some other fillers and pressed. any fillers, and maybe the coloring could have added to the weight.
I would just pop a full one, and see what happens. Keep water and a thermometer handy. If your temperature starts to get too hot, chug water. Were kinda like weed plants in a hot climate, they require more water to self cool the higher the temperature gets.