Setting up Google Ads Dynamic Remarketing via custom business feed (not Merchant Center)

Does anyone have experience with setting up Google Ads Dynamic Remarketing via a custom business feed on Shopify?

I’ve done this setup many times with Google Analytics that has been set up via Tag Manager (this allows for easily setting custom dimensions without manually tagging your site), but in Shopify’s case GA setup along with enhanced ecommerce is done via a direct integration in Shopify. I’ve yet to find any apps to create custom business product feeds and tag the site as needed. I’ve found many apps to set up dynamic remarketing via Merchant Center, but MC isn’t available in my region so this isn’t an option.

Any help would be much appreciated.