I'm considering replacing my manual Nikkor 20mm f/4  lens with the Nikon AF-S 20mm f/1.8G for shooting timelapse and landscape.  My main concern is with flicker given that it is a gelded lens.  Does anyone have experience shooting timelapse  with this lens?

I don't care anymore about any lens flicker. Since LRT4's Visual Deflicker you can remove it easily without any loss in quality. So go for that lens or consider the Sigma 24 f/1.4 art (that's what I use), if you need the 2/3 stops more for Astro- and Night Photography.

OK.  Thanks.  Good to know.