I notice that the Camera Upload feature allows the "Upload from" and "Upload to" folder to be configured, but it still seems to filter for only image or video files when deciding which files from the "Upload from" folder to upload. I expect it should be easy to remove this filter and turn this into a general purpose tool for syncing a local smartphone folder with an encrypted remote folder. Please do this! Ideally, provide a more powerful interface that allows multiple local/remote folder pairs to be configured, with the DCIM to Camera Upload pair configured by default. This feature is essential to be able to securely sync data to the cloud that is created by apps other than the camera. I can find no way to do this at the moment.
In lieu of this requested feature, I would also greatly appreciate any workarounds for automatically encrypting and uploading data to Boxcryptor.