Hi Kyle,
Hope you are keeping well.
For EMS license:
I would like to inform you that Sentinel LDK is backward compatible with Sentinel HASP so after migration, client can use old application (Protected with Hasp Envelope or API) with new EMS license.
For LDK (Envelope or API) Protected application:
It is recommended to rebuild and re-protect the application with latest LDK API and Envelope.
Thank You,
Anubhav