I had a very special problem in a timelapse today.
I filmed a dark room (telescope, full night timelapse) and then somebody switched the light on.
Now, I want this to appear in the video, e.g. I don't want to throw away the images.
But when I deflicker the sequence, Lightroom smooths out that sudden brightness change (as it should).
So what I did was a smoothing of '1', i.e. 'none', and then applied smoothing only to the bright and the dark sub sections.
However, Lightroom STILL took the bright images that came next into account when I smoothed only the dark images (and vice versa).

It would be a cool feature if there was a kind of smoothing that would only take the highlighted images into account when deflickering, NOT the consecutive images.

I can see other timelapses where that might be useful, e.g. thunderstorms.

Boris

You can apply the deflicker to a selection in the table. You can even select distinct areas (add shift / ctrl) when doing the selection. Leave out the part that you don't want deflickered.
You can also select that part only, then in the Menu "Invert Selection". Now you an apply deflicker to the rest.

Another way would be to deflicker the whole sequence, then select the area that you don't want to deflicker and click on "Remove Deflicker" above the table.

Many options :-)