With the adaptive formats Roku has started to support, bundling "static" manifests (for HLS/DASH) can make sense, in different scenarios, but when I try to load (in this instance) a DASH .mpd file from my package/tmp filesystem, the roVideoScreen gives a playback error -5.
If I host the same mpd on Dropbox, and load the file via https:// rather than file://, it works just fine.
I've tried the different permutations, all of which have failed:
Roku doesn't support locally hosted playlists. Forum user sjb64 had an interesting workaround for that by essentially running a web server from within his channel to host the playlist. You might search his posts or PM him to see if he could offer suggestions.