need exchange se for hybrid environment (opens in new tab)

We have a hybrid Office 365 environment with an Exchange Server 2016 that no longer performs any role. It does not host any mailboxes and is not used as an SMTP relay.We would like to keep an Exchange installation solely for administrative purposes through the GUI.Questions:1. Can we keep Exchange Server 2016 installed?2. If we need to install Exchange Server Subscription Edition (SE), do we need licenses for this installation, considering that all our Office 365 licenses are Business license...