https://aescripts.com/advanced-mask-editor/

• Advanced Mask Editor 2 is a powerful After Effects mask editing plugin designed for animation and motion graphics designers. It supports individual mask operations, vertex settings, mask merging/cutting/mirroring/flipping/copying, path opening and closing, moving to center, converting to shape, curvature adjustment, and mask effects. The latest version also supports animation mask processing, which allows you to easily merge, duplicate, or mirror animation masks, and has built-in 50 useful animation presets to significantly improve work efficiency and create professional visual effects with ease.