Incidentally, just because the SWC is big, doesn’t mean that an application compiled from that SWC will also be big. Library projects include everything referenced by every definition in the library. Applications that reference libraries exclude anything that isn’t a transitive dependency.

Excluding stuff for which there are actual hard references is dangerous. It is much better to try to sever extra dependencies, most cleanly by using interfaces.

You have to understand that the Flex compiler and Flash compiler only share the core AS3 compiler, and this is a pretty hairy prospect as it is, given that one version is C++ and one version is Java. The .FLA format is actually some sort of terse serialization of the in-memory structures of the C++ app, so supporting that in Flex is pretty much infeasible.

So, the question was that given that, we’d previously (Royale/Flex 1.0) gone down the path of shrugging and giving up on more than bare minimum compatibility. For Flex 2, we decided that although pure 100% source interoperability was still too hard to tackle, the best approach was to interoperate well at the SWC level. Thus, everything in Flex (and to a lesser degree, in Flash Authoring) is oriented around slinging around baskets of definitions in SWC format.

I shared many of your concerns you express here, which is why I created -link-report and -exclude and -load-externs and the Modules system (particularly the AS3 API, not the flimsy MXML-friendly facade).

Basically, until I did that, there was no solution in either product. I got a lot of grief for adding it to Flex because it highlighted its omission in Flash, but I stand by my decision to at least provide the option somewhere.

I’m a bit of an odd duck, though as typical Flex/Flash developers go, though. I just build my own stuff on top of SimpleApplication and use Flash to build pretty assets. If they’re pure media, I embed them. If they have some code attached (which I try to avoid) I link them as SWCs. I make heavy use of modules and interfaces, and other than cross-site issues and some annoyances with embedded fonts, life is grand. :-)