Thanks for the prompt reply. I know about the browsing the file tree option. What I'm alluding to is probably more along the lines of "music library generation based on folder structure" or even something like a "Play All" option at the root of a Music folder.
For example, my music is all organized like \Music\Artist - Album, so a play all of \Music\ would then in turn start at the first folder in Music, play through it (recursively) and then move on to the next. A shuffle on this would allow it to jump around the folder structure, not using the "database" Rockbox generates.
Is this sort of capability already available? Is this something I could write a plugin for or change the currently existing source to do?