The system is in place to have the difficulty of mobs scale with the presence of more or less players, so why not apply this to dungeons?
- Scale groups by numbers and statistics.
- Scale bosses by statistics and abilities. (Example: Colossus Rumbulus ceiling drop smaller radius with fewer players)
Not sure how hard it would be to apply the system, but I think it’d be easy enough and fun to be able to bring more players along.