It should be possible to use an FXPL library exported by Flash Catalyst to be used in another Flash Catalyst project. Right now, the only way is to import that library porject and all assets in there are copied into the new project. So when you change the original, your project is not updated with the new component.

Mid-sized projects will often have a base tier of pages/states, page-change interactions and their controls. Some pages will contain, as a second tier, custom components - each also having several pages/states, interactions and controls.

Bringing the custom components IN is easy. If any of these is then modified in place, it is very difficult to extract it back OUT - for use elsewhere or for going from a prototype to a production version.

The reason it is difficult is because the library panel does not allow you to export single custom components - you have to export everything and then delete the 90% you don't need. Deleting is very time-consuming because you can't select more than one component at a time; it is also error-prone because the library window jumps back to base after every change.

An alternative solution would be to allow more than one project to be opened at the same time - then the layer containing the custom component could be simply copy/pasted or drag'n'