Shopify support have pointed me towards this forum.
I have seen some people suggesting using an app that controls metafields as an option.
Would Metafields Guru assist with something such as this? Is it straight forward?
This indeed can be done in Shopify by applying specific Metafield with namespace “seo” and key “hidden”. I assume that Metafields Guru app should be able to do that for you.
You can also do this with our Shopify app Matrixify and bulk set this Metafield.
Here we do have a great tutorial that explains how to hide Shopify store’s Products from sitemap, but you should be able to achieve the same on Pages, Collections, and Blog Posts.
Instead of exporting Products as per the tutorial, you do the same for other entities.