The Cicada project, if I understand, abstracts the GSM/communication module, so its possible to implement any new module you want. Is there something that would prevent a user from expanding the Cicada project with support from the SIM5320 rather than starting from scratch?
It looks like the project is still set up to be able to easily add a new driver for a new chipset - why not add SIM5320.c/SIM5320.h here and update the project accordingly?
I ask because it might allow you to focus on the more interesting parts of your project, rather than rebuild aspects from scratch that could possibly be reused. Plus, expanding Cicada is likely to benefit existing users of that tech as well, while not preventing you from innovating and using Cicada in your final meter product.