We have been trying different options, including built-in features in the ASO tool that we are currently using, however so far the solution we have found most useful so far is using tables in Notion.
We have an ASO page in Notion per game, one for App Store and one for Google Play. See image below.
This way we are able to keep track of which person in our team made what changes, why and when. By adding some words about the hypothesis behind doing the changes, it is easier for us to go back and see when we review the results.
Not sure how this scales though, going forward with doing ASO for multiple products, and in multiple languages.