After I read that, I started rehydrating my yeast at 105* +/- a few degrees. Before that, I was rehydrating in the 60-70*F range. I also use Go-Ferm now. Go-Ferm is a yeast nutrient that doesn’t have inorganic nitrogen (DAP). DAP is really harmful to yeast during rehydration, so don’t use any yeast nutrient that contains DAP. As far as I can tell, Go-Ferm is basically Fermaid K without the DAP.
I noticed a difference right away when I switched my procedure. When properly rehydrated, the yeast gets creamy, sticky, and bubbly, just like kraeusen. If you don’t do it right, the yeast wants to drop to the bottom of the container like sludge (I guess that’s all the dead yeast).