Not at course level.
But there is this plugin:
https://moodle.org/plugins/auth_ip
can't afford to have 2 moodle servers
but is server hosting capable of virtual apaches - two moodle instances by
a different FQDN? IF so, one could have dev.site that's not in DNS
Persons needing to use dev would need an entry made in their host file
that maps ip address to none existent in DNS FQEN of the dev.site.
How many persons would need access to this course before it went live?
And from where are those folks accessing this under-development course?
What abilities would those persons need?
What If one were to create a special roll ... devsonly ... and then grant that role capiblities to see hidden courses, etc.?
One does options but one size doesn't fit all ... catch 22's etc.
'spirit of sharing', Ken