Sky-Watcher HEQ5 PRO Hypertuning

After some months of thinking, my new high end APO and some bad guiding results forced me to find my luck in hypertuning my Sky-Watcher HEQ5 PRO mount.

How does Backlash look like?

Backlash can be an ugly problem in astrophotography. How does it look like and how to get rid of it?