I had no doubt it can be made to work, but without seeing a schematic drawing of the complete supply/control circuit, I thought the issue of non isolation was a valid question.
Even home PCs don't use input transformers, but rather directly rectify the AC input voltage followed by a multi-voltage SMPS circuit, so there is a way to design power supplies to be safe and compliant with electrical safety codes, but I would not trust myself to design and build a 1,500 watt without utilizing a input transformer.
Lefty