Hey Rick,
Thanks for the suggestion. I think what you’re asking for is often referred to as macro chaining or nested-body macros. It’s not possible today although we are taking the first steps in that direction with rich body macros in development currently. That will allow users to input text in the body of the macro while editing the page.
On the Connect side of things we’ve launched the EAP for table extensibility for Connect apps which isn’t what you’re asking for, but another example of how we’re improving the ability for native macros to communicate with third-party ones.
I raise that as an example because it’s likely that we’ll provide extensibility like this on a use-case by use-case basis rather than opening things up so any macro can go inside any other macro. It’s early days though, so thanks for the feedback - it all helps.