vBArcade only supports games from third-party sources. Each source has a specific format that it arranges the games that it makes available.
Making vBArcade duplicate these specific formats makes no sense, when you could have simply kept the original game before importing into vBArcade.
Having vBArcade generate its own format makes no sense either, because only another installation of vBArcade could understand it.
Even this makes no sense, because the other installation of vBArcade could understand the games imported from their original source formats already, so you could have transferred them that way.
So until vBArcade has its own game supported format (unlikely), I see no reason to include a download function in vBArcade.