Traditionally, adaptability in communication frameworks has been restricted to predefined choices without taking into consideration tradeoffs between them and the application requirements. Furthermore, different applications with an entire spectrum of requirements will have to adapt to these predefined choices instead of tailoring the communication framework to fit their needs. In this paper we extend an executable specification of a state-of-the-art secure group communication subsystem to explore two dimensions of adaptability, namely security and synchrony. In particular, we relax the traditional requirement of virtual synchrony (a well-known bottleneck) and propose various generic optimizations, while preserving essential security guarantees.