I've never seen an NWA 757 or Airbus taxi out on a single engine...not once.
Every NWA 757 guy thinks that they are "too heavy." I wonder how quickly they'll learn that single engine breakaway thrust is minutely higher than two engine breakaway...
I presume you used to ride NWA when you were at Pinnacle? Do you ride us now? If not, things have changed as far as SE taxi mentality. I've seen it often. However, we still have those CA who don't care.
BTW, breakaway thrust in the 9 is a lot greater on SE compared to 2.