I am with earthmover in that many displaced TZR are there to improve runway utilization, I know the one in Madrid is. Making up your own "System" only messes the whole thing up as well as open you to be hanged out to dry if anything goes wrong.
Another thought is that if you are flying your one dot low app you might, due to windshear for example, sink to two dots low. Will you then automatically go around? in the end you are just eating into your safety margins.
Does the 60% (with no reverse) landing distance rule not provide a sufficient landing distance in all cases?