Have you worked out that TAR Optimiser does not run at midnight?
Normally, the OOTB default for running the TAR optimiser is 2am - 5am. This can be changed in the repository.xml/workspace.xml files. But, if you specify a start time of 00:00 it won't run.
I'm sure I've posted this elsewhere but just to re-iterate you can make the TAR optimiser run faster & do more work by reducing the optimizeSleep parameter. We've managed to get away with 0.25 without any noticeable performance impact to the live servers (CQ 5.3).