Answering my own question but leaving it up for others
https://jamfnation.jamfsoftware.com/viewProduct.html?id=379&view=info
Glad you found the PKG :-)
Before the PKG was available, we repackaged the DMG into a standard PKG using a Luggage recipe (the install payload was hidden inside the ".installData" folder on the Egnyte DMG, so we copied it from there). But using the Egnyte PKG for distribution works quite well, and solves a lot of headaches we had with the previous repackaging process, as every Egnyte update brought its own changes and issues.
Nevertheless, if you really have to repackage something, use tools like "The Luggage" or "AutoPKG" so that you can formalize, track and review your changes.