The irc chat is good, but the web client that none of us controls the code off is not good, so there is nothing to do there really. It probably would be a good idea at some point to figure out what chat clients are safe to use for linux, windows, apple computers, android phones, iphone, and put those things in the chat if we want to keep using irc.
Another alternative that may work is to set up a discord for KB and RU that is officially controlled by one of our mods/admins, that is a modern chat program that is popular. There are others of course that could work better if more security is wanted, but may be harder to find clients for.
I am not suggesting we should try to have the old flash chat back, as that won't work due to flash being deprecated.
Maybe if I rewrite the php+html+javascript+css based shout/chat box we could use that on our forum, it would basically need a single file on the server that it can read from and write to, and could prune messages after reaching a certain size for that file, but me writing code again will require me to function for that, and that is not every day for me.
I would of course want to figure out how to read the logged in user name from smf to make that a bit more nicely integrated with the forum. It should not be very hard to do that, but would require researching a bit at least.
It gets more complicated if I want to replicate pm based chat though, that irc is able to do, and multiple channels/multi user chats, also require a bit of work, maybe I will do something like that eventually and we can put it up on the server (assuming we have someone who can access the server files, I am not sure forum admins can do that).
However it is probably better to just use a competent chat that already exists with clients on all phones and desktop operating systems (discord being one popular such).