Not sure if this would be helpful at all, b/c not Squarespace specific, but I found a really helpful tutorial series re. setting up Google Shopping: https://keycommerce.com/google-shopping-course/
I'm still troubleshooting how to get my Squarespace product variant data to be included when I export csv, but overall helpful guide for syncing products to google through Google Sheets. Not as quick as doing it with a website crawl, but gives you much more control/accuracy.