Can an admin account be used to collect form data from existing envelopes via API?

We have users who have collected large numbers of envelopes and they are interested in that legacy form data.

Can an admin account be set up via API to pull that existing form data and write data labels and collected data content into a file?  Or would the sending account have to be set up as the API user who pulls this data?

It seems like the admin account should be able to, since it can be set to see into any account and manually pull form data from each envelope.

Going forward, I see Agreement Actions could be useful for *future* data. 

• https://support.docusign.com/s/document-item?language=en_US&bundleId=pik1583277475390&topicId=tkx1648575795345.html&_LANG=enus

This question pertains to *existing* data.