As I have yet to understand either RT or DT here is my take in LR 6.13.
3xHDR from the darkest and brightest image (middle one not used)
Panorama afterwards of the 3 HDRs and 3 minutes editing.
What I always liked about this workflow is that you stay in DNG all the time, resulting in a DNG of the shown image as well. They still get very large, although only 75mb in this case.