We have reports that are similar across clients, built on data sets (MySQL) that are similarly schemed. When we make a change to one report, we have to copy the latest version and change the data source, etc. for it to be reflected for our other reports for other clients - a very manual and time consuming process. We want to optimize this process by having some kind of template, or some automation that rids us of all the manual work - so when we make a change in one report, it is reflected in the others as well. Or maybe with a few clicks we can achieve the update in other reports. We looked into Linking API, but the manual process there to save and change the data access to owners credentials makes the whole effort redundant.
Open to possible solutions in Looker Studio Pro, or maybe using Google Apps Script?
While I can’t offer any insight into using Google Apps Script to automate the report data source updates, I have to wonder if you have added the data source manually from each report (which is called an embedded data source), or if you created the data source as a reusable data source (from the home page). Source: Data source, embedded vs. reusable
I think that if you created the data source as a reusable data source, any changes made to that data source would update across reports.
If you are using Looker Studio Pro, you can also try using Auto refresh for reports. More information about this functionality can be found on the Manage auto refresh for a report page.
I hope that someone else with more expertise replies and offers a possible solution if those resources aren’t helpful - in the meantime, if you are willing, you can submit the feedback to our team in the form of a feature request. The instructions for doing so can be found here: https://support.google.com/looker-studio/answer/7340016. This would help our team understand what might be happening, and improve the experience.