Not One Step Back
For 20 munitions Maxim can't be suppressed for 8~ seconds, but is immobile and can't rotate its arc. If in suppression it breaks suppression and fires normally.
It would come in useful in MG wars, when both are setting up, rushing to suppress the other or when they are already set up and you want to return fire. It's a fairly situational ability, which I'm guessing is what you want, as you you don't want to buff the Maxim by giving it an ability it uses all the time. It's also skillful, as you have to gauge before using it whether:
1. It's worth 20 munitions to suppress their MG at this moment in time and
2. If you'll be able to suppress their MG and manage not to get flanked, or worse decrewed, during the 8 second immobility.
its not like maxims don't already win all mg wars... why an ability so they win mg wars even more?