No, they won't. It'll just be annoying. If it were me, I'd add resistors across the LEDs until it stopped fast-blinking at idle. From the sounds of it, something like 47 Ohm should be plenty.
So I bought resistors and added them to the rear signal connection points, what I notice is that when the bike is just set to "on", they would blink fast. When on idle, the left signal blinks normally, the right signal starts off fast, then slows after a few seconds. What's the deal with that? Why is the left inconsistent to the right?