I did notice one annoying bug, as I change and break the code sometimes, the editor just stops working and it's hard to tell what's happening (the loading indicator just stays there). Opening the dev tools, it appears you're not catching all errors when your parser (peg.js) fails.
SyntaxError: Expected ":" or [^\t\n\r :;[\]] but "\n" found.↵ at peg$buildStructuredError (https://code2flow.com/worker-flow.js:2:12222)↵ at Object.peg$parse [as parse] (https://code2flow.com/worker-flow.js:5:1413)↵ at exports.FlowWorker.onUpdate (https://code2flow.com/worker-flow.js:5:4410)↵ at callback (https://code2flow.com/worker-flow.js:2:8619)"Font-resizing would be nice on the visual view. And killer feature would be two way interaction, but I can imagine that's a tricky one.
Here's a generic "SaaS subscription workflow" I made up in about 20 mins.
Love it!
As for $100/$300 pricing, these are on premise business/enterprise versions meant to be used by bigger teams where data confidentiality is crucial.
I think this is a great execution of a time consuming problem, good job!