I used the trial version of Supermetrics for Google Drive last month. I think it´s a great tool but it has a few flaws with respect to Facebook metrics (that I have noticed so far).
The main discrepancy I found makes reference to the monthly data for Facebook Ads ¿is there something in my query or is there a general error?
for us to investigate these discrepancies, could you please give email@example.com a temporary edit access to the file and send us a link to it as a reply to this email. Mark the queries with the issue for example by changing the colour of the cells in to red and write us thorough explanations of the issue.