Update the links in SharePoint online documents post migration

Hello team,

We are migrating our sites from on-premise to SharePoint Online.
We have documents in document libraries that contain hyperlinks to other documents stored on-premise.

Post-migration, these on-premise hyperlinks will be invalid.

We are planning the solution with the following points.

We have created a repository where we are storing the source and target hyperlinks with each migration. We will loop through each document in SPO and then find the new SPO link (from the repository list in point 1) for each hyperlink inside the document and update. This process can be slow as there are more than 300k documents that need to be updated.

We would like to know if there is any other faster and optimal solution to handle such cases.