The only blocker is the lack of dynamic connectors.
I have used the Online Web Catalogue Text Panels to good effect. The come with their own Named colours.
Ii would spend time creating the equivalent of an MS Visio Stencil of all you needed shapes and lines.
As lines readily snap to shapes the lack of a dynamic link is not too restrictive.
In fact, using Shift+C gives you a shape that can be a rectangle, a curved box and even a circle, all in one. Try that Visio.
Soft-group the same inside a diamond gives you a decision box.
Add shadows and you're there.
Acorn
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