Just like we are now going to use Hash\Algorithm across whole project thanks to #1122 by @mleczakm I think we could do the same with Unique values.
Recently @stloyd replaced all uniquid() with bin2hex(random_bytes(...)) in #1102 but I think we should take it to another level and create a UniqueFactory with following methods:
UniqueFactory::string(int $length) : string
UniqueFactory::int(int $start, int $end) : int
and that should be enough to replace most of our current use cases where we are using bin2hex(random_bytes)