With the recent research supporting that supernovae aren't a perfect uniform explosion but that it can be lopsided, doesn't it follow that a black hole won't fo

With the recent research supporting that supernovae aren't a perfect uniform explosion but that it can be lopsided, doesn't it follow that a black hole won't form with a perfect implosion? And when the singularity appears, isn't that all mass falling infinitely towards the singularity point at near light speed, and doesn't that impact the travel of the gravity waves at those speeds and time dilations to outside frames of reference? The most extreme of this would be a black hole merger I'd guess. Do they formall merge once the center of mass of one of the holes enters the event horizon of the other? Can the event horizons "brush against one another? Generally it's thought that a black hole is a perfect sphere if no spin, or a perfect oblong if not?