You should include a flowchart demo for your diagram tool. It is possible - somewhat - but you are not even including a demo for it, while vendors like syncfusion do! 

The way I found out a flowchart was possible was because of the Kendo UI cookbook and cookbook code files. 
https://www.packtpub.com/web-development/kendo-ui-cookbook

Seriously, I don't know why you are not including a demo for a flowchart in your demo list for the diagram tool; this should be a no-brainer to include, and in theory, you should not even have to build anything new, just use the diagram tool you have already made.