The next version of B4A is hopefully not far away. It will include several new toolchain components. I hope that it will be mostly transparent for the developers, but it is important for supporting new Android libraries.
Oh ! That already we are having in say, XBase++ : Parser->Compiler_>Linker.
And also in B4X : Parser (in ide) -> library extract -> java code -> compile etc., as seen in ide compile window.
The dexer step which is the step where the Java byte code is converted to Android byte code is replaced. It is a complex step and in most cases the slowest one.