S/4HANA 1511 instance - Extension of the Trial beyond 30 days with a partner account

Dear all,

Can you please help with the following scenario?

1. SAP partner wants to use the 30-day trial edition of S/4HANA 1511 FPS1 on CAL without any paid subscription for CAL
2. When the 30 days expire, they would like to purchase the partner subscription for CAL
3. With that, can the partner continue using the same S/4HANA instance, just transition from the 30 day trial to a long-term trial by installing their a Test & Demo licenses for S/4HANA and thus would be able to continue using this first instance?

Or what would be the best approach?

Many thanks.

Pavel