Tried using ksshaskpass today, neat.  One idea I had would be to make this 'just
work' instead of the manual configuration as suggest in the current README.fedora.

One way to make this work would be to drop a file into
/etc/kde/env/ksshaskpass.sh
containing:
SSH_ASKPASS=/usr/bin/ksshaskpass
export SSH_ASKPASS

This is essentially what openssh-askpass does with
/etc/profile.d/gnome-ssh-askpass.sh
(I'd argue they shouldn't put that into profile.d, but that's their bug :) )