Increase the Camera RAW Cache size in Preferences (at least 20GB-50GB recommended) to speed up image rendering.
Optimize your catalog regularly via File > Optimize Catalog to maintain speed, especially after heavy editing sessions. Adobe Lightroom Classic 2021
Utilize the dedicated Masking panel in the Develop module for precise edits. System Requirements & Performance Minimum: Quad-core CPU, 4GB RAM. Increase the Camera RAW Cache size in Preferences
Continued optimization for GPU acceleration and improved brush/slider responsiveness. Adobe Lightroom Classic 2021
Enabled easier selection of parts of an image, setting the groundwork for AI-driven selection tools, allowing for localized edits without affecting the entire photo.