I think the problem here is anything about twitch and IRC is all but ignored.
I read somewhere that twitch uses a "basic" but not 100% IRC complient custom server..
I have 3 IRC clients, all can connect to twitch chat and can chat back and forth, but the userlist only ever shows my bot in the clients userlist, no guest names show up.
But on twitch chat all the names are there, i'm only awear of a user in chat if they type something.. then their name shows up and there chat text too... but the username list doesnt show them.
I suspect this non complient irc service is the source of the problem, and twitchs custom commands.
searching google for mirc and twitch only shows videos from about 2013 at the latest.. so i assume most people only now use custom IRC code or preprogrammed bots for twitch that use the new command structure .
Why twitch cant include or leave in backwards compatibility for old complient IRC clients is beyond me..
They also added oauth so i assume security mite be involved for why the non standard code was added plus custom twitch commands too were added.