I want to upgrade to a stable release of Bind (non-beta). Does 9.4.2
have port range specification functionality? I only see it showing up in the
beta releases, but the documentation is sketchy and I don't want the DNS
server to bump on a bunch of different UDP services.

2384. [security] Additional support for query port randomization (change
#2375) including performance improvement and port range
specification. [RT #17949, #18098]

If there are other ways to do this, please let me know.