I seem to have a knack for importing objects into the Assemble Room at the wrong time in the Sequencer. Usually I think I'm importing at time 0 - I spend time positioning the object and then realize that I just set up the object for a later time. I've tried sliding the associated keyframe back to 0, copying the keyframe... but the only solution that's worked is to delete the object and reimport. Is there a simple way to move the keyframe so the positioning applies to time 0?

Delete it? That usually works for me.