I haven't seen anything mentioned about this, but is it possible to define a format for uploads. For example I think it would be great to be able to specify an optional prefix, then the name of the associated page, then an optional suffix and finally a sequentially increasing number. For example:
Maybe an option to include the page's parent name or a specific field (something category oriented) in there as well might be useful.
Adrian, the Pagefile::install hook should be triggered so long as the file doesn't already exist in the destination. Is it possible that the files are already in /site/assets/files/.../? If so, the file doesn't technically need to be installed, so the hook is never called.
As for getting the field belong to a Pagefile, this morning I've committed an update (to dev) that makes that possible. You can now retrieve the Field object that is part of the Pagefiles/Pagefile in the same way you can re