No need. Usually you don't need to open the shell when steaming. Oysters will open their shells by themselves when they are steamed. Secondly, steamed oysters without opening the shell will not affect the taste. But you can also open the oysters and steam them, which won't have any effect. Oysters steamed after shell opening will steam faster.

No need. Oysters are sweet, salty and slightly cold, and are common seafood in life. They contain a lot of vitamins, protein, cellulose, calcium, iron, phosphorus and other nutrients. Generally, there is no need to open the shell when steaming. After steaming, they will open their shells by themselves. Secondly, steamed oysters without shell will not affect the taste.

However, if you really want to open the oysters before steaming, that's fine, and it won't have any impact. Don't worry too much. Oysters steamed after shell opening will steam faster.