The ability to build and edit collections is really difficult, and it has been for years.
When adding resources to a collection, you cannot select multiple resources from your library and drag and drop them into a collection. You have to select each resource one at a time. For instance, if you want every volume in a 40-volume commentary series, you can't select all of them and drop them in. You have to select each one individually.
Beyond this taking an inordinately long time, it becomes hard to track. Visually, you don't have a clear way to tell if the resource you just dragged and dropped was added. Sometimes the drag and drop doesn't work, and you must do it again. And you can't "select" the resource in the library before dragging it. If you select it, it opens. So visually knowing where you are on the list becomes hard. Some series begin with the same name, and sometimes the name is so long that it doesn't fit in the little column. So you are dragging a sequence of titles that all look identical.
I'm very familiar with the ability to start a collection by filtering the library, but this isn't very helpful in solving the problem I just described because you can only filter for a single result. For instance, if you want to add all the volumes from the New International Commentary on the New Testament (NICNT) AND all the volumes from the Expositor's Bible Commentary (EBC), you can only filter for one or the other.
The easiest way to fix this problem is to allow multiple resources to be selected in the library and dragged into the "+ Plus These Books:" section of the collections window. Dragging and dropping multiple items that have been selected has been basic functionality in computing for 20+ years. It's mind-boggling that its not possible in software as powerful as Logos.