Actually, I'm connecting to a bouncer which supports both the PROTOCTL and CAP commands (to accommodate any client that connects through it so it does not send a NAMES-format that the client does not understand anyway).
Though it does not send an ISUPPORT/005 of its own, but simply forwards that of the server it is connected to, which indeed includes UHNAMES in it, but there is where a race condition is happening: mIRC sends out the PROTOCTL command to enable UHNAMES, and at the same time the bouncer is already sending the channel joins.
They suggested mIRC should simply request the 'userhost-in-names' CAP upon connection to avoid and eliminate the race condition.
