The documentation briefly states:

Workflow tabs control the layout of the entire page, not just what’s under each tab.

I think it’s important to list out what the “core” meta boxes are so that theme developers don’t forget to add them in. Here are some of the ones I’ve found so far:

piklist('include_meta_boxes', [
    'categorydiv',
    'revisionsdiv',
    'slugdiv',
    'postcustom',
    'commentsdiv',
    'commentstatusdiv',
    'authordiv',
    'pageparentdiv'
]);

—

Also, I’d love to contribute and add a counterpart method – exclude_meta_boxes – that adds all the metaboxes *except* those listed. I think this is important for cases when multiple plugins add metaboxes to the same page.

Example) A client is using the “Post Links To” plugin which adds a custom metabox to all custom post types. The metabox ID is “page-links-to”, but I don’t know that at the time of development. By using a blacklist (‘exclude_meta_boxes’) vs a whitelist approach (‘include_meta_boxes’) I can make my theme/plugin future proof.

Alternatively, perhaps an “Others Tab” which automatically gets added if a metabox doesn’t fit in an existing tab?

Great friggin plugin by the way!