SS specific chain is less tolerant of what would elsewhere be known as crossgearing, but it's not really the biggest factor, as 5mm isn't much and many of us are using PC58 and other stuff like that anyway for 3/32" drivetrains. The issues are weird parts wear, mechanical inefficiency, and the danger of throwing a chain. With no RD to take up tension, throwing a chain is easier than you'd think, especially if your chainrings aren't really, really round.