There isn’t a single universal order, but stitching first is often preferred for HDR panoramas because it can give more consistent tone across the final pano and reduce visible seams.

If you do HDR first, the main advantage is simpler processing: you merge smaller source images and only stitch one set. The downside is that tone mapping or HDR adjustments can vary slightly from frame to frame, making seams more obvious when stitched.

If you stitch first, the main risk is that the stitching software may align each exposure set differently, especially if bright or dark brackets hide detail needed for control points. That can cause misalignment later when you try to merge the stitched panoramas into HDR.

A practical workaround is to stitch the exposure set with the best midtone detail first, then reuse that same stitching geometry for the darker and brighter exposure sets. This keeps alignment consistent while still letting you merge the panorama exposures afterward.

So: HDR-first can work if you can keep tone rendering perfectly consistent. For many workflows, stitch-first is better—but only if you can ensure identical warping/alignment across all bracketed sets.