You can repair one side of the UV split line first, then the other. After handling the UV boundaries, use the color blending function in Photoshop to create color transitions along the edges and eliminate seams. Alternatively, you can start with a full edit in Photoshop, and if issues persist, use Blender for additional touch-ups (please note: Blender’s texture editing tools only offer a stamping feature and may run with noticeable lag).