That's obviously true. However, if you read back, you'll see that this discussion started when RF said that he would remove the Henlys which already existed (and which the OP was proposing to have replaced with an isolator).If an isolator is in place, I would obviously use it. However, fitting an isolator or a henley, is only a benefit should some some future event takes place.
As I've said, I don't feel strongly in either direction on this issue - but some people clearly do.
Kind Regards, John