Looking at the NVT4857UK datasheet I'm missing timing specifications for anything else except 1.2 -> 1.8.
I'd like to verify timing for a usage case with vcca=1.8 and vccb=3.3 as well as vccb=1.8
Further I'd expect the datasheet to talk a bit about requirements for the
"automatic direction control". There surely will be some requirements to make this work properly,
maximum length of signal reflections, transition times or something like this.