You might be more interested in the "abnormal conditions"
(a prime reason for using RS-422 or RS-485 in the first
place) than the explicit paramtrics (other than power).
Standards are met, basically, on any of them. But for
example, some only hew to the open-input failsafe that
the spec calls out, while others also deal with shorted
input or one-input-open conditions more neatly; the
input ESD tolerance also has improved across the few
decades since I did RS-422 chip designs, and modern
consumer and industrial electronics people now will
demand more product-level ESD ruggedness just because
they can (forcing you to pick a part, to match).