This looks very impressive and, as Russell says, there is a fair bit of potential demand for a good org based GANTT chart tool. I don't have time to have a serious look at it right now (preparing for teaching in a COVID-19 world...) but will do so when I can.
A quick question, however. My projects tend to be multi-year. Does the graphical presentation provide optional control of the date information along the top? We often use each year as a major divider with Q1..Q4 subdivisions for quarterly views of multi-year projects. Even just years with month labels (JFMA...D) would be good enough but full month/day breakdowns as you currently have in the demo would be unwieldy/ugly. Thank you, eric -- : Eric S Fraga via Emacs 28.0.50, Org release_9.3.7-682-geac255