Performance is related to the 5 degrees of bank issue. This has to do with sideslip, drag (DRAG is the key word....as, with an engine out, there is less thrust to overcome the drag. This is a performance issue, not a control issue.), and slipstream, fuselage drag, etc.
I don't agree entirely
As I understand things it is a control issue as well. The up to 5 degrees of bank requires less rudder input, therefore assists in controlability.
However we demonstrate the effect of the 5 degrees bank angle by showing the difference in RoC, with and without the bank angle applied.