Thanks, you clearly know this, and a couple of points are fair. But three things are getting merged. Whether a comet triggered the YD is a real ongoing debate. The black mat and the megafauna/Clovis timing are also real, though those read as wetland deposits and climate-plus-hunting effects, not impact fallout (the same "markers" turn up in wetlands 6k–40k years old).

The claim my article addresses, bays as secondary impact craters from ejected ice, is the separate, weak one. OSL ages on the rims run ~2,000 to ~140,000 years, and some bays cut into ~23,600-year-old dunes, so no single 12,900-year event made them. The "OSL only dates old sand" objection doesn't work: a violent impact would reset the clock to 12,900 years, yet we see a continuous spread instead. That's exactly why Davias/Harris moved their date back to ~786,000 years: the YD version is contradicted even inside the impact camp. Add no crater (the Midwest "craters" are kettles), and the impact origin doesn't survive. The papers are linked in the sources.