If I understood one of the options correctly it would be that there would be drops in the dungeon that you could use to later open different areas of it on another run or on the same if your party decided to. I like this idea, you could still get your quick weekly run in and if you want to later opt for the longer path which would give whatever reward. The problem does still become what do you reward for the effort put in. I don't like the idea of putting relic items behind this because you may be in a position where you just cannot get a party to run the extra bit for what you need, especially after the content is new. That has been forever the problem with changing dungeon design to be longer or more difficult, what do you offer to make the effort worth it. SE has already set the bar with the current design, so making anything more difficult has to offer more than we already get.