Zipper Noise With Flanger/chorus

when creating a chorus effect with the flanger internal dsp (starting from defaults, feedback near 0, delay around 20 ms, amount 100) there is a strong zipper noise, and sadly it does not disappear if i render…

while it can be perfectly legal to have some zipper when composing (if realtime restrictions cannot avoid it) it would be good to have a better interpolation in the dsp when rendering.

is it planned to fix this issue ?