Transclusion is a very good idea from my point of view. I saw and used it in Ivar Jacobson's Objectory tool and eventually also implemented it in my CrossLine

Transclusion is a very good idea from my point of view. I saw and used it in Ivar Jacobson's Objectory tool and eventually also implemented it in my CrossLine and other tools (see https://github.com/rochus-keller/CrossLine https://github.com/rochus-keller/CrossLine, https://github.com/rochus-keller/FlowLine2/ https://github.com/rochus-keller/FlowLine2/, etc.).