delimited, excel, json, feather, parquet, sqlite, postgresql, mysql, googleSheets
Outputs are the same (excluding databases currently). This is probably the most time consuming piece of the project if I was to expand this set dramatically given the quantity of possible connections, although here is where open source could help.
It's hard to know how technical or not technical to take this. e.g. could there be a python input e.g. arbitrary python script to pull in data? That would allow for basically any input or output. But for non technical users thats a harder sell... open to ideas.