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I have not seen the article but star collimation is a well-known method. If it is done correctly, secondary offset should not be an issue.
The proper way to star collimate is to use high magnification and defocus by a small amount. If you defocus to the point where you can see the diffraction pattern of the spider vanes then you have dofocused too much. Secondary offset will be visible and will impact the accuracy of your collimation when the star is defocused too much.
Bear in mind that star collimation can only fix the primary mirror collimation. It does not fix secondary mirror. Besides, it can only be executed reliably on nights with acceptable seeing.
Personally, I prefer to use quality collimation tools. It is an easier and a more reliable method.
Jason
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