Using content labels to filter application of a space workflow

Adding a Space Workflow by content label filter

A space workflow, if enabled will by default be applied to all content in a space. You can choose or exclude a page from having the space workflow added and applied by using a filter on content labels.

From Space Tools Workflows dashboard choose Edit: 

Choose the workflow name:

Add the content label for the pages you want the workflow to be added and applied to in space mode and choose Apply:

You can also choose to invert this label filter.