Ignore/Strip "Data Files" prefix within [sub]packages
Some [sub]packages already have a gratuitous Data Files directory in them, but would otherwise work quite nicely with bain. For example, see Better Bodies.
It'd be nice if Wrye Mash could work with archives like that.
I downloaded the file and I see what you mean. I might look into changing this but only if the Skyrim/Oblivion version would do the same.
For example:
somemod.zip
\ somemodfolder_1
\Data Files
\ somemodfolder_2
\Data Files
\ somemodfolder_3
\Data Files
That just doesn't look like anything that would work for Even the Skyrim/Oblivion versions. Even for the main version I would have to unzip it and make a new file with this structure: somemod.zip
\ 01 somemodfolder
\Meshes
\Textures
\Some Mod.esp
\ 02 somemodfolder
\Meshes
\Textures
\Some Mod.esp
\ 03 somemodfolder
\Meshes
\Textures
\Some Mod.esp
I just did that to the file you listed and now I could install it. The folder names are whatever you want them to be and the numbers are optional of course.