I am trying to eliminate hundreds (thousands?) of mosquitoes from an image. Lightroom moves slower and slower the more edits I complete. It is now virtually frozen. Each additional "spot" can take 30 seconds or longer. Can someone explain what is happening and how I can eliminate this problem so I can complete my editing process?
It's a well-known, long-standing issue with LR: The more local adjustments you do with the adjustment brush and the spot-removal tool, the slower LR will go. At some point, as you discovered, it just crawls. These tools weren't designed to do more than a relatively small number of adjustments -- if you need more, Photoshop is a better choice (as you've discovered).