SIGHUP

I'm running conserver-8.2.4, and have a large number of servers with
console sessions being managed by conserver.  Configs change often
(many times/daily), such that I am sending a SIGHUP to the conserver
to keep it aware of all changes.

The man page comments that for a SIGHUP:
changes to consoles are done "in place", resetting the console port
(bringing it down and up) only when necessary.

What defines when the console port needs to be reset?  I'm asking as
I'm seeing ports being reset in a fairly widespread fashion whenever a
SIGHUP is sent, and its unclear why.

thanks!