* I don't think the asynchronous flow can be further simplified. If you do find a sleek solution, do submit a PR, or even an issue with some sample code.
* Stack overflow is not an issue at this time (and even less in the future, with tail call optimization in V8), except for pathological objects. As such, I didn't use lodash, to keep the library as small as possible.
* JSON.parse errors are not an issue, under the assumption that the Redis database is only written to by Rebridge itself. If you find otherwise, do submit an issue. Circular references are indeed a known limitation, documented in the README.
* Thanks, I removed it in beda881. It was probably a debug line.
For the sentinel, I haven't yet had to use it (I used it in a small Telegram bot with a single Redis server on a cheap VPS). I'll open an issue for that.