this is what i do,
i almost always have my shutter open for 30 seconds (sometimes 25), and then have my intervalometer close the shutter for 1 second, then reopen for another 30. so basically your camera is working nonstop.
but the nice thing about star timelapses is, yes, it takes a long time, but if you shoot for two hours, you only shoot ~250-300 photos.
any star timelapse I have done in the past have been done using this technique. works well for me