Azure Synapse - Transparent Data Encryption
Transparent Data Encryption option should not be a simple toggle yes/no. It should put you into a wizard that shows the size of data to be encrypted and at least estimates the impact to the database and how you could monitor the progress and estimated finish time.
We turned it on two days ago and our database stopped performing this morning.
We lost valuable production cycles and it wasn't even clear if it was operating on external tables.