If that's the case, it really needs some strong docs to walk somebody setting it up for their small business through setting up an IRCd.

I was playing with all those, then I found kiwiirc

kiwiirc has it's own set of downsides. Primarily, the lack of registration requirement makes it a haven for spammers and other network attacks and their practice of putting all users onto a limited number of IPv4 addresses makes it nearly impossible to block the abuse without affecting legitimate users.

Kiwiirc admin here. We actually have a few options for networks to solve the issues you mention. We can use WEBIRC to have the network show the users correct hostname or the users IP in hex form as the username/ident. For either of these options IRC network admins can enable them at will.

Due to the limited IPv4 addresses now available we can't be using many source address for users, while IPv6 causes further questions such as what do we do for idents as they don't fit as IPv4 addresses do, and what can be done for an IPv6 user connecting to an IPv4 network?

While WEBIRC solves all the issues it does mean IRC networks must trust kiwiirc with setting user hostnames - something some networks don't want to allow making it impossible for us to set user hostnames correctly. It's an issue without a real solution at the moment.

A large part is letting IRC admins know about the options kiwiirc provides to work around the issues, unfortunately many ban all kiwiirc users causing headaches for everyone instead of looking into the options.