@kovesp: Ahhh, I see. Unfortunately, path handling is buried deep into CC. Adding auto-detect as you describe would be a lot of work and certainly break things for not very much general benefit.
There is one thing you can do that might simplify things for you. If you "backup" each of the folder settings you want to use then you can restore them when you need them. This should be faster than navigating around in CC's folder dialog and dealing with the "move books" issues. Note that you can backup/restore only the folder settings so you don't risk overwriting other settings. The next version of CC will handle running restore with "restore settings" checked when the settings are not in the backup so you won't need to uncheck that setting.
Another possibility if you have rooted the devices: create a directory at the OTG mount point. Inside that directory, put symlinks to the directories where the files are to go if the OTG device is not mounted. I am thinking something like
Code:
/storage/UsbDriveA/Books --> K4A default directory
/storage/UsbDriveA/pdf --> ezPDFReader default directory
You would tell CC to save mobi and AZW to /storage/UsbDriveA/Books, and to save pdf to /storage/UsbDriveA/pdf. When you connect your Voyage, it should be mounted on top of /storage/UsbDriveA and hiding symlinks, meaning that mobi and azw would be stored in /Books in the Voyage, and pdf would be stored in /pdf in the voyage. Voila -- the automatic switch.
Clearly this trick depends on being able to map (symlink) the correct paths for the voyage to the correct paths for the underlying device. I don't know if that is possible.
As for OTG: as far as I can tell the Google Nexus devices do not auto-mount. I have ordered an OTG cable and will test this once it arrives. In a fit of cheapness I ordered it from China for €1 postage included, so it won't be here for a week or two.