[djsarcher]

Unless you are short of local storage there is absolutely no reason to use the network (and path substitution) for Thumbnail storage, and you certainly should not be sharing thumbnails between clients under any circumstance.

I was hoping to use a network location for Thumbnails so that any thumbnails I had changed from the default would persist between updates. Is a way to backup/import a thumbnail db ? For me using a Raspberry Pi, using network storage would make it easier to avoid losing those preferences if the install gets corrupted.