It manages the same groups as shared turns and bands. Turn it off before you use bands. While both are active, Minion! keeps its groups off and warns the GM. The Minion trait and overkill still work.
Minion! reads internal values of Midi-QOL and dnd5e, and of Combat Stats before 4.4.0. A new version can change them. After updating any of them, run a short test fight before the session. See Updating.