I just noticed that traceroutes from my home to, e.g., 44.192.0.1, get stuck in a routing loop within the rr.com network. (I'm on Spectrum Cable, formerly Time Warner Cable which branded its service as "roadrunner" (rr.com). I suppose this means Amazon isn't BGP advertising these addresses yet.
Traces to, e.g, 44.0.0.1, 44.64.0.1 and 44.128.0.1 all behave as expected.
Just an observation.
Phil