Well there are EDI formats and then there are EDI XML formats, which are XML renditions of the former. Remember EDI files are plain text. EDI formats are global and standardized.
In the context of PI interfaces we use XSDs of EDI XML formats, either from Seeburger or B2B Add-on. For example, if your interface involves 850-4010 version, the xml schema for it has the core EDI schema which does not change but the overall 850-4010 XSD provided by seeburger is not an exact technical match to the 850-4010 XSD provided by B2B Add-on. Seeburger XSDs tend to be wrapped under root node LIST. B2B Add-on XSDs tend to be wrapped under root node ASC*.
Again, the difference are minor, like annotations etc. So your mappings will require minor tweaks and retest. Try to keep your old namespaces intact while generating the XSDs from B2B Add-on to begin with.
Good luck!
SM