The general rule is that on the mains side one needs either grounding and single insulation, or no grounding and double insulation. In Europe (except UK and Ire

The general rule is that on the mains side one needs either grounding and single insulation, or no grounding and double insulation. In Europe (except UK and Ireland) there us the Europlug standard plug with two prongs, that works everywhere, but no single standard three-pronged plug with grounding. For economy if scale and simplicity of logistics, double insulation is the best option, but as you note it makes a heatsink less practical.