Audio-Only title - marks (chapters) not accurate

[neilwilkes]

What timecode is used for the marks in an audio only title?
I know we discussed this in the old forums, but I cannot find any references in my notes.
All I know is that the longer the timeline, the worse it gets and is often well, well out by a matter of several seconds.

Secondly, is there a way to edit the markers once introduced?
Again, I have not found a way to do this and coupled with the impossibility of previewing with audio (which would make this easy) I do not know how to proceed
Any suggestions will be most welcome as right now it seems like a case of trial & error