I'd love to use realm, but for now i'm still hesitating. One reason is that you're using your own custom storage engine, and building a reliable one is hard. You should release some jespen-like testbench to prove how robust your technology is.
https://www.youtube.com/watch?v=4fFDFbi3toc&feature=youtu.be...
Maybe you could make videos and talks about your testing procedures. That would probably help build trust.
nb : you're not distributed, but you're enabling multi-threaded access, in an environment where your app can be killed anytime by the OS. That's quite hostile as well :)