An HDR panorama requires several HDR Photo Merges, followed by a Panorama Photo Merge. It is also common to use exposure bracketing for a sequence of similar, but not identical shots. Processing these in Lightroom is tedious, requiring waiting for the preview to complete for each set of HDR images. Once the "Merge" is chosen, the Merge itself runs more quickly (on my system at least) than the preview prep. For a large set of images, this is tedious, and the preview is un-helpful, since every time, the "Merge" option is taken with the same settings. Adding the option to use the same HDR (or panorama) options as the previous time with a "No Preview" setting would improve workflow, especially if they were launched as parallel tasks.
Does such a feature exist? If so, how is it accessed? If not, could it be considered? At least for Panoramas, PTGui and Hugin both allow all images to be submitted, with the software organizing the HDR exposures into sets, then generating the panorama from the sets. However, HDR's can be routine, especially with strong contrast subjects, with many sets of 3 or 5 shots needing to be combined into sort of a "super" raw master. A recent roadtrip left me with 100's of HDR capable shots.
Yes, it does.
Step 1) You need to do the photo merge once. The settings you use in this HDR merge will be used for the others.
Step 2) Select the next photos you want to merge.
Step 3) Press Shift + Control + H. This will start a background HDR merge process which uses settings from the first step.
Step 4) Repeat Step 2 and Step 3 for the reminder of your photos. Since this process runs in the background, you can start multiple merges and run the parallely.
Hope that answers your question.
To build on 5_nd_5's answer: If you have the photos for a single HDR merge stacked, then you can select the stack while it is collapsed and then invoke the "headless" merge (Shift+Ctrl+H). Most LR commands do not apply to photos buried in collapsed stacks, but Photo > Photo Merge does.
Many people have asked for more automation of merging. Please add your vote and opinion to this topic in the official Adobe feedback forum: Lightroom: Ability to batch process HDR brackets.