Can you use power query to track changes?

Question

I have a SharePoint library containing a bunch of templates to be completed.

Upon completion, the metadata of the document changes from pending, drafted ect to approved.

I would like to add the date of approval in my metrics as part of this exercise i.e.

As the image shows if I update the source data (First table on the left) to say Approved, then the date will update to today as desired. But If I come back to it tomorrow and update a new row to approved, the logic will cause both dates to say approved today (red) and so on.

Ideally, if I provide 100 updates throughout the year the approval date remains constant once approved, it I think it's not possible (as it needs to check what its latest updated version is) but I'm often surprised by people's solutions

I don't know if it's possible to have some logic like, If the Approval date is null then ignore, however in my mind I don't know how this can be done in power query without creating a circular reference of some sort.

Any help is appreciated.