just a suggestion for the future:
the forward firing MG15 could be fired by the pilot in real.
My suggestion would be: the forward firing MG15 could be set to marching condition by its gunner. In this conditon it can be used by the pilot aimed through his Revi sight.
Default setting should be "not in marching condition" btw
the "set/unset marching condition" the same command as the Blenheim turret and the Bf110 reargunner MG15.