Hi all,
of course you could also try to support thomas's build system ... but it seems, there's no one, who's interested in doing the work...
compiling flext and flext-based externals is pretty straightforward. One could just ignore the flext build system, building flext as a shared or static library (with the first option preferred), and based on that compile the externals. For preprocessor definitions just FLEXT_SYS=2 and FLEXT_SHARED (in the case of a shared library) have to be defined, although some more are optional.
greetings, Thomas