You don't need an import library.
If ProjectB refers to ProjectA, just reference the dll produced from ProjectA in ProjectB (as you would in a c# world). If they're in the same solution, just use a regular project-to-project reference.
Question
Is there an easy way of converting a normal Script# library into an import library for use with other projects?
I currently have to keep my 2 projects in sync - and there must be an easier way!
So just to be clear - I have a project that is compiled to js with Script#. This js library is then used as a reference library for another script# project - and so I have an import assembly that 'shadows' the library project.
Solution
You don't need an import library.
If ProjectB refers to ProjectA, just reference the dll produced from ProjectA in ProjectB (as you would in a c# world). If they're in the same solution, just use a regular project-to-project reference.