Groups don't allow different actual heights between them and this limitation force us to duplicate them and have multiple groups that are identical in plan with the only difference being the height.
This limitation creates extra work as each change has to be done multiple times, one for each duplicated group.
And that is if you are lucky enough to know which groups need to be updated for every change. This workflow leads to inconsistency and mistakes while requiring more coordination.
It also makes managing the unnecessary larger number of groups and model extremely difficult and also negates the efficiency of using groups for repetitive instances.
Changing one or more floor to floor heights when the project is advanced is the task I dread the most as it can take a couple of days of unnecessary work and frustration.
We use groups for apartment types, columns, cores, kitchen, bathrooms, etc in multi residential buildings and often the floor to floor is not constant throughout the tower.
Ideally the group will allow for heights to be from Base Constraint to Top Constraint regardless of the actual height.