No XMP files are written for JPGs even when explicitely requested

Question

Morning all,
I have learned not to trust the LR database too much. Thanks to Dan Tull I had my corrupted file repaired, but with 10,000+ tagged and processed RAWs, I do not feel too safe with the database alone. So I have decided to have XMP files written for all photographs. With 1.0 it worked only for my RAW files, not for my JPGs (have no other types).
So I was happy to find a flag "Write XMPs also for JPGs" in the catalog settings of 1.1. However, whether I check it or uncheck it, no XMP is written for JPGs. Neither when I let LR automatically write XMPs nor when I do it manually from the menu...
Anyone having an idea how to make this setting work?
Thanks,
Dirk

Answer 1

The advantage of sidecar files is that they are nondestructive to the original image. So exporting the images is no point.
And that the data written to the JPG contains all the settings is simply not the case. Try it out as follows: get hold of any one JPG in the finder. Import it to Lightroom. Do some strange manipulations on it, crop and go b/w. Then choose "Save metadata to file" from the Metadata menu in Library module. Now go to finder. The JPG is updated indeed. Copy it and import the copy into LR. The new version is the same as the original, no settings applied. And how could it? JPG is a defined format and it does not have room for most of the information that can be put to XMPs. So whatever you might expect from that export will disappoint you should you ever need it ;-)
Anyway, the issue remains: I would not expect LR to write more (e.g. virtual copies) than it does for RAWs, but I would expect it to write an XMP which is what the option offers: "Write develop settings to XMP for JPG...". How can I make it work?