AGM batteries (Optima and others) have a different voltage requirement than old school flooded lead/acid batteries.
BatteryMinder used to have a dedicated AGM unit - now their normal one senses which type of battery is hooked up and charges accordingly.
I have AGM in (most) of my car and old school batteries in the boat, power equipment and generators. My chargers get all them to fully charged status.
And - yes, I try to not put the charger on a car I have recently driven so it actually has to provide a bit of charge before it starts maintaining... so to speak.
FYI - you can run more than one battery on a single charger (at least for BatteryMinder chargers) - the batteries have to be similarly sized and of the same type (AGM or flooded). I have the Mustang and E23 currently on a shared charger - and a generator and mower on another...