Selecting the Yaesu keyer fell through to the WinKeyer branch of the settings,
which offers a serial port picker and a Connect button. So the operator went
hunting for the right port — trying the standard COM and the enhanced one in turn
— and neither connected, because this keyer uses NEITHER: it keys over the CAT
link already configured in Settings → CAT.
It now has its own branch, like the Flex one: a speed field, the warning when the
CAT backend is not a Yaesu, and a line saying explicitly that keying rides the
CAT link. Speed changes go to the rig's keyer instead of a WinKeyer that is not
there.