For me it's tough without knowing what the standalone and network versions "do". As-in: does your module provide a client only to access a server (not part of your module) on a remote (or local) system?

I think if you're providing the client and server aspect in your distribution, then the connecting to localhost is the way to go. If you're only providing one half of that client / server relationship in your module, I would deal with the headache or potentially spin off the ::Standalone version if I could make the change transparent to any current potential users. If that ::Standalone broke the API, then I'd just stick with managing the local and network results separately.

Then again, I'm not that good a programmer, so most of my work is probably redundant anyway and so I wouldn't notice how inefficient I was being.