Just an Idea:
A Crucible Mod run should be savable (if possible) so that it can be continued later if necessary.
Sometimes you don’t have that much time, but you could still use that time for the game.I can imagine it might be difficult because of all the points, etc., but it would still be a great added value.
The fact that this mode will be playable in co-op has already been almost announced and represents the best improvement. The Mod itself is one of the best Idea of the whole franchise 
thank you