So many fancy brands don't have hacking seconds... How can I set my Patek Philippe exactly, some of them don't have second hands and some of them with second hands don't hack. I think the majority of the Pateks in my collection aren't able to be set exactly.
Faux hacking isn't good for the movement, but not usually damaging to the movement. The situation is more serious if the watch is a Tourbillon - the Tourbillon will not take to faux hacking and reversing very nicely (since the Tourbillon cage itself can't spin backwards).