The idea has been suggested before, and might get implemented later in an enhanced version. The problem is that once we get into defining left and right side-bearings for individual glyphs — which you need to do when designing cursive scripts — font design starts to get complicated.
The idea behind Scanahand was to make font design easy for those who are not experts. If you want to do cursive scripts, you can adjust side-bearings and add kerning to the font with FontCreator Home Edition or Professional Edition.
See Dave’s Tutorial on Joining Flowing Scripts to understand better what is involved.
See also my post in this thread.