I'm not sure if it's in the MoI interface philosophy, but it would be much more clear if the curve are showed in yellow during the construction or points edition .
It's sometimes hard to clearly see the curve you build, more over if there is some geomtry on the screen ... (geometry than might be usefull as reference)

Here's some visual exemple, more easy to understand that my english :o)

How MoI show a curve when you build it:


More clear view:




How MoI show a curve when you build it:


More clear view: