Why does Merge to Panorama not allow rendering in Lightroom?

Question

If I choose to Edit in Photoshop on one or more images, I get prompted that Camera Raw 7 may be needed for Photoshop to render the images correctly - which I understand as the versions of Camera Raw are different - and then get three options to choose from: Open Anyway, Render in Lightroom and Cancel.
However, if I choose Merge to Panorama the only options are Open Anyway and Cancel - I assume this is the same for Merge to HDR although I haven't tried it. So why can't Lightroom offer the same Render in Lightroom option when merging to panoramas? It's possible to work around it as I am currently doing, but it's a bit convoluted: Edit in Photoshop, Render in Lightroom, manually initiate Photomerge, save the resultant TIFF in the correct place, sync the folder to import it, then delete the original TIFFs Lightroom created that I didn't really want in the first place.
I'm assuming this is an oversight that will be corrected in the final version - would be nice to get that confirmed though!

Answer 1

I would guess that Render-in-Lightroom choice doesn’t apply when the number of input files (the RAWs in LR4) doesn’t match the number of output files from Photoshop (a single panorama or HDR file).
In the normal Edit In Photoshop situation the file you are rendering in LR on the way to Photoshop is what Photoshop is going to save to, so LR doesn’t need to delete any temporary files.  When you make a panorama or HDR there are intermediate files that would need to be cleaned up, and instead of being an oversight, maybe it is just LR trying to be simple about things.  Simple means that LR is not going to create and delete intermediate files for you along with not asking you how the temporary files should be named or where they should be created.  The lack of camera-raw would be a rare and usually transient condition so would be a low priority in the overall scheme of things to implement a solution for.