I have used the "exploded view" many times so I would say I'm not exactly new to it.  What I do is in SW 2015, when I do an Explode Chain, with "auto-space components on drag" I get it all set and grouped as I like, no problem there.  The problem arises when I "pack and go" or have to revise the assembly and add components, does anyone know of a way to add a component or sub-assembly to an existing chain group? Hopefully the screen shot helps with my explanation.