Zero values essentially tell Shoe Last Maker that you are working with a template that was developed in an older version of the plugin that did not have that parameter. The workaround is to use a number close to zero, like 0.1 for instance.
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Not currently, and probably not for quite some time.
You can’t import external shoe last CAD models exactly. What you can do is put them on a temporary layer and then […]
These would be isocurves. You can turn them off in the display settings of Rhino by setting them to zero width: Tools/Options/View/Display […]
Your relevent FAQ answer.