Unless something has changed recently.
It has.
I just made some simulation and simulating 15000 JOIN message with /parseline -q to 'properly' add nickname to the nicklist is just taking ages, it's not viable and note that I was hiding the window and hiding the join event message with on ^*:join + haltdef to speed it up.
Using the raw 353, it's almost immediate, which is why I was toying with it (but I just tested it again to confirm).
I was using JOIN message because I need to simulate a /mode as well and wanted to do it 'properly'.
However, it looks like mIRC understand the NAMESX protocol regardless of the proper handshake with the server regarding it (Twitch does not support NAMESX), so I can add modes that way directly with the raw 353.
