Bring back the possibility to stop a Collection from being synced AND stop photos in that Collection from being synced as well, in one-step.
Since LR CC 2015.7 this happens when you stop syncing a Collection (clicking the little sync icon or deselecting Sync with Lightroom Mobile via mouse contextual menu):
(Now you have to go and find those photos in that Collection from All Synced Photographs and remove them from there. Too many steps, too cumbersome and too easy to make a user error.)
There still is the requested option to remove photos at the same time when you delete a Synced Collection instead of just stopping it from syncing:
That same option should appear for just stopping the Collection being synced as well.
The first dialog for stopping a Collection from being synced is messy altogether as it asks if the user wants to "Stop syncing these photos?" but the button for doesn't actually stop syncing the photos and instead keeps those photos synced to LR Mobile and Web and just stops syncing the Collection name.
So at least more correct title could be "Stop syncing this Collection?" and that's not enough as there needs to be a way to stop syncing a Collection AND stop syncing photos in that Collection, in one step (unless they are part of another Synced Collection).