On the KR4/D4v2.5 driver the RC filter values are 3.3K and 1uF, imput that into a calculator (That one for example) with the frequencies given by Gchart to see the ripple.
Edit : you might indeed not visually see it, personally I probably wouldn’t either at that frequency, but I get headaches and visual discomfort, especially on monitors with PWM.
Like Gchart mentionned a way to reduce that ripple is to increase the capacitor value, the downside is that it slows down the response, with 10uF for example for it takes 0.1s to rise to ~95% of the desired output, not really a problem for turn on/off, but for strobes/candle it might be.