It is app specific. It is unlikely for instance you will upload a small file (which would only be a datamap) to a public place and not encrypt the data map. So if you upload say a bunch of files in a directory structure then you will have a single data map of the root directory. You would store that securely, even in your loginpacket/account which is encrypted.
What I mean is that you upload chunks (self_encrypt does that) but not data_maps. The data maps can be concatenated into a large file and self_encrypted again to produce another data map. You just secure that in the app somehow (many options). So I don’t see anyone uploading a private file data_map anywhere public, if that makes sense.
The low level API would be access to the store call where you could store an immutable data item that is anything (so not from self_encrypt). So from the low level API you could bypass self_encrypt and upload a files, if it was less than 1Mb.