You dont always want to listen to your teachers NM because there talking rubbish. Semi slack lines semi fixed rigs is what i use for majority of my fishing. Semi slack lines increase indication no matter what your lead set up is because haveing a drop on your indicator gives it more travel which allows it to do what its meant to which is indicate.
Sometimes i use semi slack lines back leads and semi fixed leads your teachers would proberly say thats stupid but my album says different.