I finally got some clear sky to try a test with the mount settling time set to 2 seconds instead of 30. In order to maximize the dome motion and time spent slewing, I slewed to an object in the north so that the dome went from az 180 to az 45. It worked fine. So my previous issue, which appeared to be fixed by putting in the large mount settling time, was probably due to some other cause. SGP does indeed appear to wait until the dome driver reports slew complete. I should have looked at the logs when I was having the problem, but just tried to work around it instead. Next time, if it occurs, I'll check the logs.
Thanks,
Kent