Development stalled out in 2018. Since then, there's been some notable events:
Kerbal Space Program 2 was announced in 2019, and hit Early Access in 2023. At this point, my interest in KSP1 has mostly fallen away, so development on this library is 100% on hold at the moment.
I don't know if there will be a kRPC (or equivalent) for KSP2, or what it might look like. But I imagine that if/when it happens, this library will likely be resurrected and ported (or rewritten) to use it.
Elixir released GenStage, a much better way to create an events pipeline. Technically this was in 2016, but it took me until much more recently to discover how useful it is.
The entire SpaceEx.Stream system could probably be rewritten using this. I
might still want to put some syntactic sugar on top to keep things clean from a
library user's point of view. And, of course, the entire future of streams
will depend on what our KSP2 RPC API (if any) looks like.