I look at it as a matter of how close to the edge you plan to run your fuel system. If you're going to run it at 100% duty cycle and wide open, you probably want each injector to flow perfect.
But if you haven't CC'ed your combustion chambers. Your heads weren't machined by CNC mill, and your exhaust ports aren't perfect, well then you already have plenty of stuff out of balance in your motor, so whats one more thing.