Hi @markk26,
There is currently no way to add these attributes with NitroPack for compatibility/stability reasons. Throughout the years we have identified cases where adding these attributes can cause stability issues with carousels, gallery plugins and sliders. This is why we have developed a more elaborate method to achieve the same effect of preemptively sizing images but without using these attributes. So even though you might see this recommendation in your Page Speed report the underlying issue is actually solved, just in a different way.
Regards,
