I would suggest to only optimize anything when it is needed (either because of performance issues, or because the current system is hard to work with).
If your server can deal with the current architecture and there is enough network bandwidth, I would not complicate my life with manual data synchronization, global variables, single network call, etc., because the end results seems much harder to work with and easier to mess up / introduce bugs.
But since you mentioned each machine has a dedicated flow, I would rather try to simplify that (just like in programming: DRY principle) and implement the generic flow only once and call it with different parameters via link in/out+call nodes.
Also don't forget to set the default context to persistent file storage.
