How can you use an LGPLv2.1 licenced AS3 library in a proprietary Flex app without “giving away the farm”?

Question

Consider a Flex (actually AIR) application that is considered proprietary, but needs to use an LGPLv2.1 AS3 library, so that it is considered a "work that uses the Library" according to the license text and is thus required to be distributed according to the terms of Section 6 of the LGPL. What provision in AS3 or Flex is there for using a "suitable shared library mechanism" (Section 6b) to create the executable to use the library, allowing the end user to replace the library (somehow) and debug the new lib's use, thus not requiring that all the source for the proprietary app to be supplied (Section 6a,c,d,e) for recompiling/relinking?

I've already had a false start with RSL's, because replacing the RSL causes "Flex Error #1001: Digest mismatch with RSL".