Originally Posted by crossi
If I have 3 separate libraries I know I won't be able to keep the same changes in all of them the same.
It would be nice if I could within the same book designate mobi(1), mobi(2) and mobi(3) for my 3 kindles but the program won't let me.
I would seriously advise against manually copying the versions you need in and out of the library folder- you're bound to break something sooner or later if you mess around in there manually. At the moment, the most practical approach, in my opinion, would be using three libraries. You can put all the books into one library, fix up the metadata, then copy the books over to another library (see the right-click context menu) and replace the MOBI file. That will guarantee that the books get the correct metadata as of the moment you copied them, but it will not keep them synced. (But then again, how often do you edit metadata once you get it right?)
For the record, you could get around this situation if you removed the DRM from your files. However, depending on where you live, this may or may not be illegal to do. Also, as per forum rules, you can't ask for help on how to do that here.
This would be a Good Thing to have, though. You should consider adding a ticket
requesting the ability to add multiple copies of one format to the library.