Possible to recover files after running secure erase on external drive?

After writing zeros 7 times the chances of recovery are slim to none. Of course, anything is recoverable if you want to spend the time and money. But it probably would take a team of forensic experts to string the files back together.

You can try using Prosoft's Data Rescue but don't get your hopes up.

https://www.prosofteng.com/datarescue-mac-data-recovery/

There is a free trial to see if it can recover what you need. But don't do another process on that drive until you've downloaded and run it.

SSD-drive data is gone, essentially the moment you delete it.

After overwriting, even once, no software alone can get your data back from a magnetic drive.

Dis-assemble in a clean room, and use a laboratory equipment to detect the partial magnetic fields that may have been missed when it was overwritten.

The only guys who are thought to be able to do this work for the US National Security Agency (NSA). But if they told you about it, they would have to kill you, because it is so secret😝

it can be attempted by some very intensive data forensics lab technicians but you're not going to find off the shelf software or some terminal hack to get the data back.

No. That is the whole point of a secure erase that the files are not recoverable. File recovery software will not be able to recovery anything for you.