Keep Magento. Add WeRefund.

Two view-only API resources, chosen under Resource Access › Custom: Orders › Actions › View (Magento_Sales::actions_view) for your orders, including the customer details recorded on them, and the refunded total on each, and Content › Elements › Pages (Magento_Cms::page) for your return policy page. Leave Save Page (with Edit Page Design under it) and Delete Page unticked — untick them if the Admin ticks them along with the parent. WeRefund doesn't ask for Credit Memos, which in Magento also allows creating credit memos. You approve what you ticked with Allow when you activate the integration, and you can revoke access at any time. WeRefund signs each call with OAuth 1.0a, so the setting that lets integration tokens act as bearer tokens, introduced in Magento 2.4.4, stays at its default, No.

WeRefund reads the CMS page you chose on a schedule and, on every read, compares its content with the last version it recorded. It reads the page content as stored, so write the policy text in the page itself, not in a CMS block or widget inserted into it: a block edited on its own changes neither the page's content nor its update time, and isn't seen as a change. WeRefund doesn't ask for access to CMS blocks, which in Magento also allows saving and deleting them. WeRefund also reads whether the page is enabled: a disabled page isn't treated as your published policy. A change to the content is recorded as a new version and verified again; if it stops passing, verification becomes unavailable. Each time WeRefund records an order, it captures your published policy page for that order, so each order keeps the version captured for it.

Adobe I/O Events for Adobe Commerce requires Adobe Commerce 2.4.4 or later and isn't supported on Magento Open Source. Adobe Commerce Webhooks are synchronous calls, which Adobe advises only when synchronous communication is critical. Scheduled reads work the same way on Magento Open Source and on Adobe Commerce on cloud infrastructure or on-premises, and need no events module or App Builder project.

Not in the way this page describes. That edition doesn't support integration tokens — its API access goes through Adobe IMS — and its customizations run as App Builder applications rather than modules installed in the store. Talk to Sales about it.

No. You refund as you do today, in your Magento Admin or with your payment provider. Magento updates the refunded total when a credit memo is recorded, as it is when you refund from your Magento Admin. WeRefund reads that total and, if your store takes payments through Stripe, PayPal, Adyen, Checkout.com or Airwallex, the refund from that provider, and records it against the order in WeRefund. It never creates a credit memo, never refunds in your place and never holds your customers' payment funds.