While I understand the point -- hinting to the implementation -- is it really something we need, in the sense that is CSS the right place for this, rather than handling these situations better in the browser implementation?
In some circumstances the heads up is totally required. For example if you're on a low spec mobile device with a relatively high resolution display, you're in a situation where you can't build a layer for an animation you didn't expect. And your memory footprint is so low so you don't want to be building layers unless you need them. If you don't have the heads up then you're going to drop the first few frames of the animation and the experience is going to be janky every time.
If you're in a situation where it's not required, then I would advice against using it FWIW. I still work on optimizing web frontends and I almost never use this property because I rarely need it.
One of the meta-solutions you've missed is the establishment of "Baseline", which helps web devs understand what features and capabilities are safe to use. I hope this helps! https://web.dev/baseline
> Represents the formula max(minimum, min(limit, max-content)), where minimum represents an auto minimum (which is often, but not always, equal to a min-content minimum), and limit is the track sizing function passed as an argument to fit-content(). This is essentially calculated as the smaller of minmax(auto, max-content) and minmax(auto, limit).
Are you sure this is happening on the CPU? I thought the CPU-side only generates a list of paint commands but the GPU does the bulk of this job.
My knowledge is dated and second hand though. New GPU APIs hopefully changed this!
