Example: I have added certain sites to the blacklist, but this applies to the entire network. How do I open websites for certain ip addresses?
You need to create your customs acls, you will to know how to edit files on shell.
Check this post, you must read about squid acls rules if are not familia with or you will cry.
https://forum.opnsense.org/index.php?topic=16171.0 (https://forum.opnsense.org/index.php?topic=16171.0)
And please use the terms allowlist and denylist instead of those old fashioned biased words.
come on, I'm a old dog, but yea, new words to learn.
But it works, with opnsense we have to type like a good Unix sysadmin, love it, this give power but, with care.
Good day.