The timeline in standalone seems to round the "duration" value down to the nearest second. I have to adjust the length of the scene steps to work with that limitation which is cumbersome.
For example, I have 2 of the 18 available scene timelines loaded with 3 second long scenes that I want to stop right before they hit the end, so I set the duration value to 29. That value will only stay until I toggle from one scene to the other. When I come back to the original scene the duration value has changed to 20 instead of the 29 that I set.