Watching with interest here Ben.  What version of Acumatica are you running?

Currently running build: 22.215.0056  with the commerce connector to BigCommerce. 

@BenDurrant , those additional fields are not available for mapping for us in the connector, by default. If you wanted to do that mapping, you can either hardcode it through Acumatica customization, or you can create a customization that would add that mapping capability to the connector. Former approach is generally leaner and less expensive.

@BenDurrant You’d be better off using custom fields in BigCommerce to export this data from Acumatica. Then a few simple theme updates should get these displayed on the storefront for you if that is what you’re trying to do.

Thanks for the responses, we specifically wanted these fields against the variants which we have as matrix items. Mainly because we vary some of our products by there sizes (Tables). Spoke with our consultant and they advised that there is no out of the box dimension table which we thought was crazy. It would be good to see a Matrix entity in the commerce connector for mapping reasons. 

@BenDurrant You can set this and export it as a custom field from the Template Item, but it would have to exist in the Template Item screen, not just the Stock Item.

You could also try creating this as a Variant Attribute for the Matrix items. Good luck!