The 2nd Con
No linting or other introspective tooling. The only checking of correctness is syntactical but on the other hand linting makes no sense in a visual flow based programming language. But other tools would make sense, for example path discovery between two points in the flow, i.e. how many flows send a specific email?.
Seems to ignore the existence of nrlint a linting tool for identifying potential problems with Node-RED flows