Falcon is catching subtle coding issues that MXMLC didn't catch like duplicate variable declarations, ambigous definitions and more. Therefore, there is a good chance that when you compile an existing app with Falcon you might have to fix some of your code. So far, I haven't seen anyone want to make Falcon less 'strict'.
But I just ran into an issue with resource bundles where the current Falcon code reports a compile error if it can't find a bundle for a locale. MXMLC seems to do some magic and makes the en_US bundle also act as the bundle for the locale that is missing a bundle. It has to do that because the SDKs currently throw an error if a locale is missing a bundle. But is that what we want? I would think you should get a warning if a bundle is missing and the SDK should change its code so that if a bundle is missing it just falls through to the next bundle in the locale chain, if any. But such a change would mean that, if you compile an existing project against an older SDK, even Apache Flex 4.10.0, your app may throw an error if you are missing a bundle. Thoughts? -Alex
