Hi @PMike ! Thank you so much for your reply. I was hesitant to use the Script Editor approach since Shopify declared they were going to deprecate it (https://changelog.shopify.com/posts/shopify-scripts-deprecation); hence why I was trying to maximize Flow.
For the time being I was able to put into place a workaround. We’re reading the product metadata when we Add To Cart, and will set a line item property that way. It’s not perfect (because the SOT can change between add to cart and order submission) but it works for most instances.