iirc Mike’s always said that the stabilization had to be done by hand. I think he used the image registration software to fix warping.

He now says (at 21:32) he had to register all elements of each frame by hand.
https://youtu.be/G3W_O-tp0_g?t=1253

But what he describes after this is manual gate weave reduction. If you want to align every feature of the frame, you need something like a grid-based transformation, which is very hard to do consistently by hand over 1000’s of frames.

Maybe his tool did automatic registration, but with the option to override the transformation when the program does something wrong. That would mean he actually had to really verify it frame by frame and make corrections before composition.