I'm brand new to this but I think I successfully shot a day of sailboat races (5,500 images in .jpeg). Trouble is, during shots (let's say) 3,500 to 3,800 a piece of something blew onto my lens. I think I could easily remove it in LR with the Spot removal brush and synchronize over those 300 images; but I'm not sure how that interacts with LRTimelapse. Any advice would be appreciated.

Thanks.

Hi, you can do that. Just do it as a very last step in Lightroom after completing the LRTimelapse process. Manually synchronize the Spot Healing tool to all needed images and then export the sequence.