a little bit of lurching between the value changes
I wonder if that could be the 8-bits-per-colour resolution of all addressable strips. Only 256 intensity levels are available in each of the red, green and blue channels. Because the eye is not linear, a difference level of 1 is not noticeable for levels over about 100, but for low levels, it can be very noticeable indeed. For example level 2 is obviously twice as bright as level 1!
I seem to remember FastLED has a "temporal dithering" feature which might help. I've never used it, but here's a link.