No real risks to be honest. There are many new stable features on every major version. V10 was rock solid to me and my team. However I needed to go v11 in order

No real risks to be honest. There are many new stable features on every major version. V10 was rock solid to me and my team. However I needed to go v11 in order to get stored procedures, a feature our data scientist required and based on his Oracle SQL background this was a necessity. 9.6 is old now. I'd upgrade. Get pgadmin4 while you're at it.