Based on “What’s New” in Photoshop CC 14.1 help, there appears to be no support for asset filenames containing spaces, commas, or plus signs, all of which are legal Windows filename characters which can make filenames a lot more readable. Allowing filenames to be double-quoted would allow these characters — and a lot of others — to be used without ambiguity. If this capability is not present, please add it and address it in the Photoshop help file.
Also, it’s not clear assets can be generated from open PSB or TIFF files. If they can’t, please add this capability and address it in the documentaiton.
Finally, the only assets that can be generated appear to be png, jpg, and gif files, all of which are used for the Web. There are also reasons to create flattened files from layers and layer groups in other formats including TIFF, PSD, PSB. Please add support for these three formats, as well as any others whenever there is an identified need.