As far as I know, there's no way directly in Keyshot without editing directly the parameters of each animation. For instance, if you have a turntable animation set to rotate 360 degrees and you only want to capture up to 270 degrees, then just set your turntable to only rotate 270 degrees.
Now, you can render frame duration to only capture/render a certain amount of the animation. You would just need to stitch the sequences together later on. You could also set your work area for the duration you want and then just render the work area, then reset to render the next are you want and stitch the different renders together.
Subsequently, you could also just render the whole thing and then go into a video program like Premiere and clip down your sequence how you want it. The downside to this is you have to render everything, which maxes out your render time.
Unless there is a compelling reason to render everything in one complete go, breaking it up and rendering chunks at a time will be your best bet and most economical, and you can queue them up to render one right after the other.
