Some features are very impactant for the group organization. For example, the "Awareness between ledger settlement and year-end close" feature has a very big impact in terms of organization, because it will force ALL companies for a group to be at the same level of closing, means ALL the companies must have close the fiscal year at the same time (that is impossible in the reality).
So the big impact is that we must wait for all companies closure, before to be able to install the feature (otherwise the closing will be impossible in companies that have not already closed the fiscal year).
This behavoir is due to the feature that does not allow to process closing for cross fiscal year settlement, so we must deactivate and then reactivate but for ALL companies (the deactivate is a Microsoft advice as no other solution si provided in standard).
So it is clear that in this case, a feature activation by company will consideraly facilitate the closing process for a group that can have 30, 40 or more companies).
Thanks for your help.