Why bottoms need their own workflow
Trousers depend on waist position, rise, inseam, leg shape, hem, and interaction with footwear. A generic outfit prompt often changes several of these at once.
Use a dedicated Replace bottom action. Provide a full front reference plus details for waistband, pockets, hardware, and fabric texture. Ask the system to preserve the model, top, pose, camera, and scene.
For a local correction, segment the trousers first, refine the mask around hands and the top overlap, then submit the masked edit.