Why Umbraco.FilleUpload is not supported for blocks?

[PeterKvayt]

I have faced with this warning:

Could someone please describe why Umbraco.FilleUpload is not supported for blocks?

If it is because on each content save Umbraco.FilleUpload wraps value? It is fixable (Umbraco.Cms.Core.PropertyEditors..FileUploadPropertyValueEditor):

If it is because we get contentkey and content type key as empty guids? It is fixable too (see this issue).

Or maybe it’s unable to track whether a file has been deleted, preventing it from removing it from the file system? Yes, it’s quite a challenging task, but I believe I’ll find a solution.

Can someone explain this or share a reference to a discussion where it has been addressed?