Does it possible to erase the automatic extruded form given by the position of the cursor before you choice "Set Dir"
because it's pertubating for enter the 2 points of Direction!
Curiously that is erased for the "Set Path" but not for the "Set Dir" !
or there is a particular reason that I have missed?

PS does exist a script for select automatically only "generator curves"
there is a script "Select by type" So we can use "Curve" but if want only curves who has generated something?
Maybe this will be resolved by the futur's objects system;)