I'm trying to optimize my shaders by making certain features toggleable, but I wanted to know which method was the most efficient? I've heard using conditional statements in shaders is generally frowned upon, so I thought I'd ask just to be sure.
You should definitely go for Static Switches whenever possible as they are more performant than conditional statements that execute all functions before comparing their results.
For additional information on how Unity handles this type of behavior, be sure to check the link below.