Apollo client link change after creating apollo client and websocket connection

I have a use case to use websocket link only if a feature flag is enabled. Are there chances to change link given to ApolloClient instance after initialization.
Also wanted to know if creating websocketlink open any websocket connection, or resources are only consumed on executing a graphql subscription?

I believe ApolloClient is only structured to support adding links at initialization/construction time, but I could be wrong.

When we changed something similar (in code from a few years back), we tore-down the client instance and reinitialized it.