Hi,

I have a timelapse of the milky way with a lot of flickering. I am not using dehaze and I am using the camera colour profile.
I am using shadows and highlights, both on the image and on a filter, but what can I do? I feel like the curves don't work as well, and I have no other way than to use shadows and highlights on the filters.

Thank you for your help.

https://youtu.be/Z7NelqIpJBc

First thing I'd do is to set a reference area to the sky (leave out the outer parts where the image vignettes).
Then apply multipass deflicker with a couple of passes.
Working with reference areas is explained in the deflicker tutorial on https://lrtimelapse.com/tutorial/basic/
If you still have flicker after that, it's contrast flicker caused by LIghtrooms tools.
I've explained in the Expert Tips video #5 how to detect and solve this: https://lrtimelapse.com/tutorial/expert

I have Milky Ways like that too - even with zero editing in Lr. Is Flicker Free plugin worth using, or does LRTimelapse deflicker do the exact same thing? A few top timelapse teachers recommend Flicker Free - even after LRT deflicker

If you didn't apply any edits, it should be luminance flicker which LRTimelapse can usually remove fully if you set a good reference area (see deflicker tutorial on https://lrtimelapse.com/tutorial/ )
LRTimelapse uses a lossless visual approach that features multiple passes - that's why you can get the curve really smooth.
If you still see "flicker" despite a smooth pink curve, it's other effect, that might be more local (like headlamps) or contrast effects (for example introduced by Lightroom) which will be hard to remove with any deflicker software because they are not really flicker.