Why we train lifts with tempo

I came across this study on training with tempo on OPT's website.

The following is OPT's synopsis of the study as well as OPT's further explanation on the importance of tempo.

Nice Andrew Charniga Jr translation of a study on tempo for beginner lifters (0-2 years trained weightlifters) - 2.5 sec tempo I believe referred to the total time it took to do 1 rep; something like 2 sec down, 0.5 sec up is what I'd guess - interesting to note there were differences seen even from 2 sec to 2.5 sec to 3 sec in tempo. As with tempo, there are many reasons to have speed associated with lifts - for 1. control, 2. test/re-test, 3. pick on weaknesses in movement, 4. establish a hormonal response based on the tempo given, 5. elicit more or less potential of muscle fibre activation based on concentric prescription....and more (which are covered completely in OPT CCP Assessment)...as well as sometimes when speed should NOT be associated with lifts.