A window for Selection Groups [plug-in]

[optigon]

Ran13 I think was talking about EMPTY groups, not invalid. It seems to me That invalid groups should disappear as soon as possible. I assume that the delay is on empty groups. Let's call a spade a spade.
I have not idea what Optigon's old menu text was ... but sounds like it should say "Delete Empty Groups".

It was a command for deleting groups for which matching geometry no longer existed.

Regardless, the root of the problem is that the model changes and the groups do not. Groups only remain current for models that do not change. Deletions, extrusions, cuts, and any command that changes a model's geometry has the potential of messing up a Selection Group.

You could make an extrussion that makes a SelGroup invalid, and then undo the extrusion, making the SelGroup valid again.

Groups are probably better for Objects, since their Ids don't change when modifying their geometry. Groups based on Vertices, Edges, and Faces are more easily made invalid.