Panorama - Photomerge is removing person

Rather than alter the masking and blending from Photomerge, which could end up with edges that no longer quite fit, I would treat it the same as any other composite.

Duplicate the layer with the person and move it to the top of the layer stack. The duplication is so that you leave the rest of the merging and blending untouched.
Delete the layer mask on that duplicate layer

Mask the person on that duplicate layer so that the panorama becomes visible in the background. Watch for any shadows - you may need to include them/add them.

Dave

Your doc should have a separate layer for each of the photos, with Layer Masks. You can paint on the masks with black or white so show or hide the various layers. It can be helpful to temporarily reduce the opacity of one or more layers, to more easily see where you would need to do your painting, restoring to full opacity when done.