The state of IRC on the Mac is a really sad one. So disappointing. All the good clients haven't been updated or maintained for at least five years now. :(
I get that IRC is kind of a niche service but there are still hundreds of thousands of people using it. Yet all we have left on the Mac is Textual. One single IRC client.
And even though I try to like it its more of a love-hate relationship. Some of the features work well while others (like assigning my own keyboard shortcuts) never have for me. And while people using mIRC on the PC can just right-click-block a user in Textual you have to open the Ignore List from the menu, click the [+] button, add the nick followed by some syntax, then, save, then save again. Then hope that you did it right. If I am missing the easy option, I'd love to know. I don't think there is one.
The Mac is supposed to be the easy one, the user-friendly one. Its apps should reflect that. Unfortunately Textual -- at least from my point of view -- does not. Unfortunately it's all we have left now, there is no other choice.