Triggered manually or when a product is updated.

Auto tag products if their inventory policy is set to "continue" (aka Continue selling when out of stock is checked) and remove tag if it's "deny"

Additionally, the ability to include a pre-order date metafield into the equation.

For example, I have a metafield for a product's release date called "po_date" and I have two products with continued inventory policy. Product A's po_date is January 2017 while Product B's po_date is December 2023.

I'd like a tag for Product A (wherein today's date >= po_date) as "backorder" while "preorder" for Product B (wherein today's date < po_date).

I can show different messages for these products on the front end but would be nice to have it synced on the backend so a collection could be easily made.