If you are making a video comprised of several clips it is suggested in the manual to begin the next clip using the last frame of previous clip as a reference. This is to maintain consistency.
In last webinar I asked if they could add somehing to easily capture without taking your clip into a video software to grab a frame. They might do that but meanwhile here is a quick method I found.
Import a video into Iclone. Right click on the workspace viewport and select “save last frame” from the options.
Hope this is useful !