Hi,
I take my astro photos with dithering. My problem has also been that it take some time for the auto guiding to stabilize after every dithering, about 15 to 20 seconds, earlier much more.
I try to not do to big dithering moves, about 10 to 20 pixels on the main camera (color camera), then it work.
My main camera is a Canon 6D which has low static pattern. I only dither to take away the hot pixels.
Here I have write it down how I use the dithering:
http://www.astrofriend.eu/astronomy/...dithering.html
/Lars