First of all, thanks for the great module, this makes creating and managing multiple custom views RSS feeds so much easier.
However, it would be even more awesome if there was an extension module for MRSS, so I could add- media:content xmlns:media="http://search.yahoo.com/mrss/" - to image/photo fields - which is required by some services to be able to style RSS newsletters.
I managed to rewrite the rss_field_formatters enclosure module to pull this off quick and dirty. However, this only works with the one RSS feed in the display view mode, as you are unable to create additional RSS display modes.
If I have time this weekend I will try to rewrite one of the current extensions to accomplish this objective.