Moving CCK Fielgroup tabs to heavy #pre_render call

Well, I'm starting this up as a placeholder at this point. I'm totally buried trying to wrap up a project here, but hopefully this will inspire me to come back and complete this when I can.

Basically it's becoming more and more important to move CCK Fieldgroup tabs out from hook_form_alter call to be something like a heavy #pre_render call. For two main reasons:

1) CCK is making more use of later calls in FAPI flow. For example it now (as of 2/13) assigns #weights of non-cck fields (title, body, etc) in a #pre_render call. So a field like body will no longer have it's weight assigned when FG tabs comes and modifies the form structure. So at this point it's a bug if people are using a "default" tab and doing weighting on the body, etc.

2) AHAH callbacks get to be more and more of a mess.. already an issue for that.

I think a heavy #pre_render call is where FG tabs will have to live if we want to jump in after CCK is truly done messing with the form. However I don't yet know how nested fieldgroups will add to the mix here either :/

So at this point if anyone has info to share or ideas that would be great. I will get back to this, as I make heavy use of tabs on this project and I want to sleep better at night :)