Switching personalities of a system (FAS, AFF, ASA AFF) is not supported. To obtain an exception, have your NetApp sales representative file a Feature Product Variation Request (FPVR).
As per the netapp documents, you can switch from AFF to ASA (one way only) but there is no mention of the other way. Hence, I doubt that's possible. But, you could reach out to your NetApp account team to confirm this understanding.
Switching personalities of a system (FAS, AFF, ASA AFF) is not supported. To obtain an exception, have your NetApp sales representative file a Feature Product Variation Request (FPVR).