I do a lot of Ken Burns style time lapses, zooming slightly in or out to create more movement and action in the sequences.

Because Lightroom's crop function is very good for doing this animation (much better than punching in numbers in Premiere Pro imo), I mostly do the zoom directly in Lightroom. Another advantage is I'll get maximum image quality (files are not resized twice), and the file sizes are also much smaller on the way to Premiere Pro, a big difference when you work with 4k video from 46 megapixel RAW's for instance. The disadvantage is obviously that I have to re-render the whole sequence if I want to change the zoom.

After upgrading to 5.3 i noticed that the previews are very shaky when doing a slow zoom, like there is a severe camera shake. I suspect it may have something to do with number rounding when you resize the image for the preview. As if I were counting to 100 like this: 10,9,8,7...20,19,18,17...30,29,28,27..

Not a big issue really, just a bit annyoing because it's a good thing to know in advance whether or not the sequence needs to be stabilized in After Effects/Premiere. But now, all the sequences with crop animation are shaking.

No need to put a lot of effort into this bug, but if you have the time

Regards,
- Jørn T

You are right, it might be the rounding, but normally that shouldn't be visible as strong as you describe. Without a video recording, it's hard to say if you did something wrong or if that's normal.
The Previews have always been like that, nothing really changed in 5.3 regarding this.
LRTimelapse has not been specifically designed for smooth preview of ken burns animations, since I still feel, you get a superior quality, if you export in render in original size and do the ken burns in video processing.
Also you can preview the ken burns in the camera preview mode (visual previews off) then you'll see the animation as a orange rectangle going over the screen. Check if that looks ok, otherwise send me a screencast of the problem, and I'll have a look.