Honestly Bungie has already shown that there is no reason they cannot create a "Normal (Private)" and "Normal (Matchmade)" option as needed. This should ALWAYS be an option for every difficulty. Made it default to the matchmade setting when you open the node, sure. But at least give us the option to elect to do an activity privately if we prefer. In the case of Sunless Cell there are actually two reasons. First is story content getting omitted if you are forced into a join-in-progress. The second is the for exploring/hunting fragments for the exotic intrinsic quest. In the later case forcing matchmaking just sets up conflict by having fireteam members potentially working at cross purposes. And the answer of "well just have a full fireteam" is a silly answer when we KNOW they have the ability to just allow a private setting, as they've already DONE IT on many activities now. Just make it standard for heck's sake. The community has only been asking for the ability to control matchmaking at all difficulties basically since the game launched.