I perused the code and it was written in a C++03 style. Pointer chasing and manual memory management in the few files I poked through. (IE, no unique_ptr, just new/delete).
This may be perfectly safe... however, I'd give it a few years of battle testing before touching it.
Here's an example:
https://github.com/bloomberg/blazingmq/blob/main/src/groups/...