MusicTechHelpGuy shows two quick ways to route Summing Stacks in Logic Pro once your mix is grouped.
First, create effect sends directly from a Summing Stack, useful when everything inside that group needs to hit the same reverb or delay without setting up individual sends per track.
Second, nest every instrumental track into its own Summing Stack. That gives you one fader to solo or mute the whole instrumental bed at once.
This nested stack also speeds up stem prep. When a client wants instrumental and vocal stems, you already have a clean split ready to bounce.