Hi Aaron,
Greetings from Syncfusion.
We are unable to reproduce the reported issue at our end. The sample which we have tried at our end can be downloaded from the following link.
In the above sample we have used an hidden some rows and column in the Excel file and converted that Excel file to HTML. The HTML output is as excepted i.e., the hidden rows and columns are not rendered in the output HTML file.
We have shared the output HTML file in the Output folder of the sample for your reference.
You have mentioned that Currently it exports the hidden columns/rows and sets them to zero width/height and we find this is proper. We request you to explain your query again. If you are using AutofitColumns(); or AutofitRows(); then the hidden columns or rows will be resized and exported to HTML. Kindly remove that code if you are using it.
Kindly look into the above sample, modify it and share us the issue reproducing sample along with Excel document you are using at your end, which will helpful for us to investigate the query and provide prompt solution at the earliest.
Also please confirm the Syncfusion XlsIO version your are using at your end.
Regards,
Keerthi.