Is your feature request related to a problem? Please describe.
While there hasn't really been much need for custom options for a group, I was creating a custom function for a dynamic group sorting method, I found myself setting vars in the sorting function itself which isn't really ideal.

Describe the solution you'd like
Custom options was created to give users the ability to easily interact with custom code and I think it'd be nice to have a custom options section for the group itself.

Describe alternatives you've considered
Setting vars in the groups sorting function, which I feel is a little messy.

This was largely the motivation for the child_envs value you have access to in group sort/layout custom functions. It is a bit clumsy, and a bit of a hack. Unfortunately though, I'm not keen on adding bona fide options that live on the group itself.

Really, the main problem with the idea is, how to distinguish between options on a group child, and options on the group itself? Should they be on separate tabs? If so, we risk annoying users with yet another tab - that list is getting fairly large. If not, then should they somehow merge with the child options, like we do with options on sibling auras already?

I haven't figured out a solution that makes me happy. So, I'm going to close this request, because I don't expect to be able to find a workable solution better than the workarounds we already have.

I sort of envisioned having the custom options tab be completely overwritten by the group's custom options. Since I don't really see people needing to mass edit custom options that frequently, since custom options tabs are usually extremely unique. I'll have to look at the child_envs thing. Thanks for letting me know.