what security dialogs? and what race conditions? do you know what that means, or are you just throwing around words?
if you mean the "verify your new device" dialog, yeah, it has a problem. it won't appear most of the time on clients that were not open when you sent the verification request from the new device. I don't know why, and this is not comfortable, but then I can start verification from a device I already have, and it will work. or I can also just fill in the password from my password manager, which you surely have too.
but I haven't seen other problems with it recently.
XMPP at least functions reliably, if you ignore all of the protocol extensions and use it like IRC with images of course.
which does not even have a bolted on security that way.
Though the main and only good Android client got archived.
calling element classic good is a bit of a stretch. it was very slow.