On the Korg PA the markers can be very specifically targeted at timing points. This can be edited down to an individual tick if required..they can also be named whatever you want...

And you can have as many as you want. No restrictions.

The ONLY minor annoyance is that one cannot assign hardware buttons(or footswitches) on the panel to operate it. The markers page is the only place you can select them from and this sits on top of whatever window is open. Mind you, it is quick to get to with just a double button press from the right side of the display (lyrics and score pressed together)

One of the advantages I suppose of having the ability to have more than four mark points.