This would be a really helpful Feature for a future release.
storing metadata like grids/cues/Loops outside the Audio file generates a single Point of failure - the database. in case of rb the specific metadata are stored in multiple Folders with dependencies - that's from IT view a quite dangerous Scenario.
if the metadata is stored into the tags one can prepare and analyze on different machines and Transfer them easy to the main/dj Workstation maybe with just rebuilding the waveform new (like it is handled in Traktor).
serato has till now the best mechanism to store metadata, they store simply all, including the stripe into the tag area of the Audio file - a well proven method for years now.
would be so great so store at least the grid/cue/Loop data into the file especially with the great Feature of flexible grids it makes big sense to store this data directly into the file a "safe" place for the hard work of flexible gridding :-) writing this data into the tag area is no rocket science.
maybe an idea for future Releases?