I've written this explanation before, but boosted breeding and the diamond temple are only truly effective if you speed breed. If you think about the mathematics of it, it is clear. If you do not speed up breeding at all, you raise your change of breeding a diamond from 1% to 6% (for example). Over the space of one week you might get maybe 20 attempts in, during which you chances have improved only a little bit. However if your goal is to speed breed until you do get a specific diamond hybrid well you just saved yourself 5/6ths of the cost, which is a huge saving as splitting means that you could be spending hundreds if not thousands of gold in 100s of attempts.