This is two questions in one but they are related.

I've watched all the tutorials and looked through the forum and can't find the answer.

I'm deflickering footage that was shot on sporadically cloudy days. The deflicker works well with luminance changes but not colour changes. My sequences naturally shift between bluish and orangish depending on whether a cloud is overhead. Is there a way for Deflicker to fix this as well as luminance? My scenes are of snow so colour shifts are very noticeable on the white snow

If there isn't a way to do it automatically that leads me to my second question:

If I have to key frame this wb change using the key frame wizard I need to be able to pick which frames key frames are on. I can't figure out how to choose which frames they are on. My work around is to add lots of key frames and delete the ones I don't need before dragging to LR. But this is time consuming.

Thanks in advance and sorry if these questions have been answered.

Deflicker works on luminance changes. It doesn't do any WB adjustments.
The situation that you are describing are natural changes in color perception, which I wouldn't remove from a sequence, that's not flicker. Maybe you are editing way to heavily and Lightroom exaggerates that color casts?
In the more than 10 years now that I'm doing timelapse professionally now, I've never had a case where I thought about removing white balance shifts on a daylight sequence like you described. I'd really like to see that one, if you wouldn't mind to share it!

As for the keyframes: just go to the position in the sequence in LRT, then with the key "1" you can set a keyframe, with the key "0" remove it. Another way is to just click on the little diamond left in the table for the row where you would like to set or remove a keyframe.

I'm only doing light editing in LR and I'm avoiding the controls you said to avoid.

Ok that's good to know about adding the key frames.

Is there a way to toggle between your processes frames and the original so you can see if you've introduced errors? To do this I've been initialising the sequence but then I have to start again every time.

I've uploaded 2 small sequences here for you to see. Original and processed.

https://wetransfer.com/downloads/6e90372...133/060846

One of the main problems with that sequence is, that you shot it with very short exposure times. This makes the snow and people pop in and out. You should always use an ND filter during daytime to get longer exposure times. It will make your timelapses look so much better.
As for the white balance: I find that color cast changes stange. are you sure you have set the Whitebalanced to a fixed (non auto) value in Lightroom? If so and you still get the casts, keyframing might be your best option.

You can switch between camera previews (without editing) and the edited raw files by toggling visual previews on and off.

Ok. Thank you.

Oh to answer the question about white balance. It is not set to auto.