Every feature can be implemented and is up to Khaled. Does this post really add anything to the discussion?
The problem with adding "purely cosmetic" features is that you can add hundreds of them and users will still ask for more. This is why mIRC is scriptable, so that K need not add a special editbox for every single character you want echo'd to your channel window. The two lines of code given on the previous page are more flexible than any option dialog could ever be, and are already implementable *now*. Why not just accept this and use it?
Would it work? Yes. Is it necessary? No. Is it simpler? If all you're changing is <> to , maybe. But what if you want to change the way the nick prefix is displayed too? Another feature suggestion for another editbox to customize that? The scripts are short and are already available for you to copy paste and modify. How much simpler can it get?