I wonder if a kind of hybrid programming would be possible which switches between this dataflow-like functionality for parts and more traditional ('large blocks of text'-based) techniques for other parts.
I was working on a simple framework a while ago where the highest-level organizational structure was a 'domain' and these domains would connect to one another via 'converters'. I think the dataflow format would work really well for defining and linking up domains, and small functions that do things like filtering would work well within converters—but then maybe within particular domains it's somewhat of a free-for-all again (i.e. you use traditional programming techniques). Just thought I'd share the idea on the off chance that it sparks something for ya—I'm not really doing anything with that project at the moment.
I'm also curious why you prefer the tabular format over something graph-based. Is it just that it's more straightforward for people to lay things out/organize?
Although my goal is to use it to understand how we can write software better.