I’m going to pipe up here and say how unexpected and amazing it was to see multiple marker tracks slide into Cubase 9. I just had to say something.
I’ve been asking for this for a long time, and it’s going to help my workflow tremendously.
So…
THANK YOU!!! 
Makes things so much cleaner.
For example:
- You can have one marker track dedicated to just your export/stems cycle markers.
- One marker track just for making revision notes on parts of your session
- One marker track for location / punch points
- One marker track in Linear timebase so you can mark timecodes in your session which stay at their origin timecode even if your tempo track changes while working. Hugely useful for film/TV composers.
- One marker track for visual locations of intro/verse/chorus/etc if you don’t want to use the Arranger Track for that purpose.
It allows you to switch workflows / headspace by activating the marker track that you want to focus on. When writing, you can make your creative notes heads-up. When recording, you can engage your punch points or cycle markers track so your location recall key commands become useful without getting mixed up with all the rest of the markers in your session. When exporting, you can switch to the stems marker track and only see those show up in the Export Audio window.
Icing on the cake: you’re able to drag&drop/Copy&Paste markers from one marker track to another.
Endless uses and can only get better.