good - you will notice that fingers flying much faster on the keyboard without that politeness thing getting in the way.
couple of thoughts -
1) perhaps, you are in the same trap as the mid ct ball theory, in the sense that the benefit of your target system is in the 'targeting', not the 'target'... i.e. player becomes more aware of a specific spot to shoot for, better concentration, better execution, (some golf teacher ask student to aim for a specific leaf on a tree 200 yards away..... same idea)......but there is no intrinsic benefit of where that target is, which leads to my 2nd thought..
2) limiting depth risk, at what cost......... aiming 6ft-9ft short of the baseline sure will give up lots of short balls waiting to be pounded.... you say well, joker lands his balls there.... I am saying, yeah he lands them there, but he is not aiming there.