TWITCHCLIENT 1 twitchnotify subscriber

Just use the same client but with 2 connections. No need to open a 2nd client for that.

on *:connect:{
  if ($me = nick1) { twitchclient 1 }
  elseif ($me = nick2) { twitchclient 2 or 3 }
}

Then use /scid and /scon