Well, if we expand arbitrary the range of programs reading ~/.ssh/config, then we can put there whatever we want, can't we? The point was that SSH won't read the password from its config file. There's a good reason not to do that: this configuration file shouldn't contain sensitive information because it's a plain text file. But, maybe you can encrypt it -- something I've never explored...
Well, if we expand arbitrary the range of programs reading ~/.ssh/config, then we can put there whatever we want, can't we? The point was that SSH won't read the password from its config file. There's a good reason not to do that: this configuration file shouldn't contain sensitive information because it's a plain text file. But, maybe you can encrypt it -- something I've never explored...