I'm not at a computer where I can create something reproducible now but I'll try to post some code soon.
You mentioned saving the parameter values and reassigning them after regrouping. This is what I tried to do. The problem I'm running into is these are project instance parameters specific to each group instance. So when I'm regrouping the groups afterwards the instance parameters are being set to the group I'm changing them to. (Using... Group.GroupType = ModifiedGroupType all of the instance parameters are set to the instance parameters of ModifiedGroupType)
Maybe there is a different approach to this problem?
Again thank you