yes, I know about the problems in rendering! :)
I had planned to deal with them later, once I get some encouraging results.
For example,
* I can add a column to multiply the actual duration with a large factor to get a workable width
* I can move the label outside the node and rotate it by 90 degree
(I haven't really tried this feature, but I think it is possible)
* Where duration is 0, I will replace it with a small number to get a thin node. (the only penalty is that I have to declare that the diagram is not to scale.)
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I had not paid attention to the presentation tab, but when I checked it, it was blank. I put a tick in the check box. Now I get a stack of nodes with labels, but they are somehow arranged in a diagonal arrangement. (I am still referring to the unmodified excel file: I haven't yet carried out the changes described above.)
[Please let me know how to insert image in comments, so that I can post the screenshot here.]