RE: [css-transforms] Individual transform properties, stacking contexts, containing blocks

> Having a default 'none' (and every other value establishing a stacking context) is probably best so that animations that sweep through the zeroes (translate: 0px, rotate: 0deg, and scale: 1) don't pop in and out of stacking context/containing block.

That sounds good to me.

> Didn't we decide that stacking context doesn't change during animations, as if will-change were applied if any keyframe has a transform?

The problem I see with an assumption like that is that we would still have to define the default values for each property as not establishing a stacking context outside of animations.  That would still lead to jumps for script-driven "animations".  Or for transitions that happen to start/end at a default value, which may be especially unpredictable/uncontrollable for transitioned values applied programmatically rather than through a static stylesheet.

Thanks,
-Matt