I went looking for this idea today to add my vote and was amazed that this idea is not already on the board. If I missed it somewhere, please let @kimberly_fuhrman-jones know.
I'd like the ability to save a group (Detail or Model) as a family. We can save the group as a project, why not as a family?
When selecting Save As Family on a group, it would take you to the Family Template folder to select a Family Template to start from. Then it would copy those elements into the family. And then you could save the family.
Detail Groups should be simple I would think.
Model Groups would be a bit more tricky, (system families, system family hosted families, etc.), but I'm sure the Autodesk engineers could figure out some tricks! Or give the feature some exceptions. e.g. No system families or system family hosted families in the Model Group.
Thank you!